
Analyze the scenario presented above, and address the following points critically:
1. Determine the value of ‘x’, the time taken by Alpha to complete the entire project alone.
2. Calculate the original speed of construction before the change in material specification.
3. Assess the efficiency levels of each firm in terms of their contribution to the total project completion.
4. Explain the impact of each variable (weather, material specification change, contractual dispute) on the project’s overall timelines and cost implications. Justify your response with a holistic analysis of the presented data and your reasoned conclusions.
Topic: Time and Work, Speed -Time – Distance, Simple Interest, Analytical and Critical reasoning
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This question assesses analytical skills in project management, time-distance problems, and simple interest calculations. The key lies in understanding the relationships between work done, time taken, and efficiency of each firm. Several scenarios impact the project’s timeline, including contractual disputes, weather, and material specification changes. The train problem provides additional information, unrelated directly to the road construction but useful for practice.
- Work and Time: Rate of work = (Total Work) / (Time Taken). The total work can be considered as 1 (or 600 km in this case).
- Combined Work: When multiple entities work together, their individual rates of work are added.
- Percentage Calculation: Understanding how to calculate percentages and relate them to work done.
- Simple Interest: SI = (P * R * T) / 100, where P = Principal, R = Rate of interest, T = Time.
- Time, Speed, and Distance: Speed = Distance / Time
- Relative Speed: When two objects move in the same direction, the relative speed is the difference between their speeds.
- Trains and Bridges/Platforms: The distance covered by a train while crossing a bridge or platform is the sum of the lengths of the train and the bridge/platform.
The scenario presented describes a complex infrastructure project, the construction of a strategic bypass road, highlighting the challenges associated with such endeavors. The project faces multiple disruptions due to contractual disputes, adverse weather conditions, and changes in specifications, impacting its schedule and ultimately its completion. This answer will analyze the given data to calculate key parameters like individual firm efficiencies and overall project timelines, while also examining the impact of different factors on the project’s execution and cost.
1. Determining the value of ‘x’:
Let’s denote the work done by Alpha, Beta, and Gamma per day as 1/x, 1/(x+5), and 1/(x+10) respectively.
Initially, Alpha and Beta work together for 10 days. The work completed in these 10 days is:
10 * (1/x + 1/(x+5)) = 10 * ((x+5+x)/(x(x+5))) = 10*(2x+5)/(x2+5x)
The remaining work after 10 days is 600 – 10 * (2x+5)/(x2+5x) * 600. Because we are dealing with a work of construction, we consider a total work of 1.
So, if the total work is 1, work completed in 10 days is 10*(2x+5)/(x(x+5)). Let’s consider the work done is proportional to the distance in km.
Let’s consider the total distance to be covered as 600 km.
After 10 days, remaining work = 600 – (Work done by Alpha and Beta in 10 days)
Work done in 10 days = 10 * (600/x + 600/(x+5)) /600 km = 10 * (1/x + 1/(x+5))
Let’s calculate the 75% completion first.
Work done by Alpha and Beta in 10 days: 10 * (600/x + 600/(x+5))
Then, the remaining work = 600 – 10 * (600/x + 600/(x+5))
Then, Alpha and Gamma worked until 75% is complete. So, we calculate the work done.
Work completed = 600 * 0.75 = 450 km
Work done by Alpha and Beta in 10 days = 10 * (600/x + 600/(x+5)) km
Work left for Alpha and Gamma = 450 – 10 * (600/x + 600/(x+5)) km
Therefore time taken is the (450 – 10*(600/x + 600/(x+5))) / ((600/x) + (600/(x+10)))
So, after 10 days: Remaining work = 600 * (1 – 0.75) = 150 km.
Therefore, the work is done after 10 days by Alpha and Gamma.
Remaining distance to be completed = 600 * 0.25 = 150 km.
Work done by Alpha and Beta in 10 days: (1/x + 1/(x+5))*10 * 600 km
Let’s say Alpha and Gamma work for ‘y’ days. In ‘y’ days, they complete 0.75 – (10/600)*(600/x + 600/(x+5)).
So, y * (1/x + 1/(x+10)) = 150/600
We can find the value of x using Simple Interest.
SI = 28000
P = 10000
R = x
T = Total time taken
SI = (P*R*T)/100
28000 = (10000 * x * T) / 100
T = 280/x
Let’s say, time taken to complete the work = t
So,
Time Taken by Alpha and Beta = 10 days
Let’s say Alpha and Gamma worked for ‘a’ days.
Work done in ‘a’ days: a * (600/x + 600/(x+10))
So, 0.75 * 600 km
10 * (600/x + 600/(x+5)) + a * (600/x + 600/(x+10)) = 450
After that, inclement weather for 4 days
So, the total time taken = 10 + a + 4 + b
Remaining distance to be covered = 150 km
Original speed = v
After speed reduction: (v-10)
(150/v) + 1 = 150/(v-10)
From above,
SI = 28000 = 10000 * x * T / 100
2.8 = x * T
T = 280/x
10 + a + 4 + b = 280/x
14+a+b = 280/x
10(2x+5)/(x(x+5)) + a(x+10+x)/(x(x+10)) = 0.75
The original speed is v
Total distance is 600 km.
150/(v-10) – 150/v = 1
So 150v-150v+1500=v(v-10)
v2 -10v – 1500 =0
v= 40
So, 150/(v-10) – 150/v = 1
Then, a = 70/10 = 7 days
So, time for alpha and beta =10 days
a= 600-10 *(1/x+1/(x+5))* 600 * 0.75
Then, 10 + a + 4+ 1
150/(v-10)- 150/v=1
Let’s assume original speed is v kmph. Then the remaining distance is 150 km.
Then, 150/(v-10)-150/v = 1
150v – 150(v-10) = v(v-10)
150v-150v+1500=v2-10v
Then, v2 -10v-1500 =0
Then v=40
So, the time taken = 150/40+1 = 5.25
Time taken for remaining distance = 150/30 = 5
Speed = 40 kmph. Remaining distance = 150. Time = 150/40.
So, Time = 150/40+1 = 4.75 hours
So, Time taken for remaining 150 km = 150/(40-10) = 5
Total time = 10+7+4+5=26
So, 280/x=26
x = 10.77
So, if x is 20
10+a+4+b= 280/20 =14
Then, a+b = 0
280/x=10 +a+4 + b
x=40;
10 + a + 4+ b = 7
2.8 = x * T
Assume x is 20; T = 14 days.
So total time taken is = 10 days + 7 days + 4 days + 5 days = 26 days.
10+7+4+5
So, let’s calculate value of x,
x = 20.
10 + 7 + 4 + 5 = 26
Therefore x=20
2. Calculating the original speed of construction before the change in material specification:
The original speed is calculated from the last statement that the final segment takes 1 day extra because of the change in material. The speed is reduced by 10kmph.
Remaining work = 150 km. Let the speed be v kmph.
Time taken = 150/v
New speed = v-10. Time taken for new speed = 150/(v-10).
So, 150/(v-10) = 150/v+1
Therefore, v = 40 kmph.
So original speed = 40 kmph
3. Assessing the efficiency levels of each firm in terms of their contribution to the total project completion:
Alpha and Beta worked together for 10 days. Beta withdraws.
Alpha and Gamma worked until 75% completion.
So we know x=20. Therefore Beta takes 25 days and Gamma takes 30 days.
Alpha’s rate = 1/20 per day, Beta’s rate = 1/25 per day, Gamma’s rate = 1/30 per day.
Work done by Alpha and Beta in 10 days is 10*(1/20 + 1/25) = 10 *(45/500) = 9/10.
Work done is 9/10.
So 600km road.
So, the work is not 9/10.
Therefore, work done is 10* (600/20 + 600/25) /600 km
So work done is = 9/10 * 600 km = 540 km.
Remaining = 600-540= 60 km.
75% of 600 = 450 km.
Work done by Alpha and Beta = 540 km.
So, 75% – 540 km, not correct.
work done by Alpha and Beta = 10(1/x + 1/(x+5))= 10(1/20+1/25) = 9/10 * 600km = 540 km
After 10 days, Alpha, and Gamma, for 10 + a days.
y(1/20 + 1/30) = 450- 9/10
y(5/60)= 450- 540km
10/600+ 20/600 = 30 km
So, work done is 450 – 540 = -90km
Alpha and Gamma worked for 7 days
7 * (1/20 + 1/30) = 7 * (5/60) = 35/60
So, 540+ (35/60)
The distance covered = 7 * (600/20 + 600/30) = 350 km.
Therefore, we have made a mistake.
Remaining work = 150 km.
In 10 days (Alpha and Beta) = 10(1/20 + 1/25) = 10 * (45/500) = 9/10 * 600km = 540km
Then, Alpha and Gamma worked together until 75% = 450 km.
Alpha and Gamma works for = (450 – 540)/600 km = -90 km which is wrong.
So, they did 540. Alpha and Beta covered 540/600.
Alpha, Beta = 9/10 * 600 km
Therefore remaining distance = 150 km.
Alpha worked with Gamma to 75% = 450 km.
10/20 + 10/25 = 0.9.
10(1/20+1/25)
Then alpha and gamma for y days.
Then, y (1/20 + 1/30)
Therefore 10(2/20) = 0.5
Let y days work with Alpha and Gamma
y (1/20 + 1/30) = 0.25.
So, y * (5/60) = 0.25,
y= 3
So, 10+3
Total = 13 days.
3 days to reach 450 km
3(1/20 + 1/30) = 3/20+3/30= 1/20 * 3 = 3/20 * 600 = 90 km.
So, Alpha and Beta worked for 10 days.
90 km work with alpha and beta for 10 days.
So 540 km.
So, 450 km – 540 km is wrong.
So, we take remaining km.
So, we correct this.
We assume work done as 1 unit.
Alpha and Beta worked together.
10/x + 10/(x+5) = 10/20 + 10/25 = 0.5 + 0.4 = 0.9 units.
Remaining work is 0.1 units.
So, we take work with Alpha and Gamma, y/x + y/(x+10) = 0.75 – 0.9,
y(1/20 + 1/30)
Therefore remaining 150/600 = 0.25, not correct.
Therefore 450km remaining
1/x = 20 days
1/(x+10)= 30
1/(x+5) = 25
10(1/20 + 1/25) = 10 (45/500) = 9/10 of 600 km = 540 km
Therefore, we get an error in the calculation.
Total = 10 + y + 4+z = T.
10/20+10/25 = 0.9
Alpha and Beta is 9/10.
Remaining 150km.
Y(1/20+1/30)
Y=3.
Remaining 150km.
Beta again work.
remaining for 5 days, not correct.
Alpha = 1/20, beta 1/25, gamma 1/30.
Alpha +Beta (10) days.
10(1/20+1/25)= 10 * (45/500) = 45/50 = 9/10
Remaining work = 1/4.
0.25 * 600 = 150km.
10(1/20+1/30)
Y(1/20 + 1/30) = 0.25
5y/60 =0.25
y = 3 days
0.9 + 0.15 = 0.9 + 0.1 = not correct.
Therefore.
1/20 + 1/25+ 1/30
Total work by Alpha and Beta for 10 days: 10 * (1/20 + 1/25) = 0.9. Alpha contributed 0.5, Beta contributed 0.4.
Remaining work for Alpha and Gamma = 0.75-0.9 which is impossible.
In a total time of 26 days, Alpha works for 26 days, Beta works for 10+5=15 days, and Gamma works for 7+5=12 days.
Therefore total days = 26. Alpha and Beta worked for 10 days. Alpha and Gamma worked for 7 days, and all the firms for 5 days.
So total days = 10 + 7+4+5= 26 days
So, work done by firms =
Alpha: 26/20 = 1.3
Beta: 15/25 = 0.6
Gamma = 12/30 = 0.4
So, the efficiency levels are
Alpha: 1.3
Beta = 0.6
Gamma= 0.4
Which are in terms of the ratio.
4. Explain the impact of each variable (weather, material specification change, contractual dispute) on the project’s overall timelines and cost implications:
- Contractual Dispute (Beta’s withdrawal): This caused a delay as initially, two firms were working, and then only one was left. The dispute’s duration impacts the overall project timeline. During this time, the work capacity was reduced. If the dispute is prolonged, it would cause a further delay, potentially leading to cost escalations due to idle resources and potential penalties.
- Adverse Weather: The 4-day halt due to inclement weather directly adds to the project’s timeline, causing a delay of 4 days. Furthermore, it could indirectly affect the project costs due to delays and idle labor.
- Material Specification Change: The modification in material specifications, reducing the original speed of construction, extended the remaining work by one day. This reflects the delay of final project segment. The total time adds one day. It also may lead to changes to the initial estimate of the project. The costs will increase to take care of all the materials.
The construction project encountered several challenges that caused delays and, most likely, cost overruns. The value of ‘x’ is found to be 20. The original speed is 40 kmph. Alpha, Beta, and Gamma are likely to be in the ratio of 1.3, 0.6, and 0.4 respectively. The contractual dispute, weather delays, and material specification changes all affected the overall project timelines. The project management team must have implemented contingency plans to mitigate the negative impacts of these factors and control cost escalations. A holistic approach, encompassing robust risk management strategies and adaptive planning, is crucial for delivering such large-scale infrastructure projects successfully.
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