Aptitude & reasoning

Surds A surd is a square root which cannot be reduced to a rational number. For example,  is not a surd. However  is a surd. If you use a calculator, you will see that  and we will need to round the answer correct to a few decimal places. This makes it less accurate. If it is left as , then the … Read more

  Boat and stream problems is a sub-set of time, speed and distance type questions where in relative speed takes the foremost role. We always find several questions related to the above concept in SSC common graduate level exam as well as in bank PO exam. Upon listing the brief theory of the issue below … Read more

  Introduction Money is not free and it costs to borrow the money. Normally, the borrower has to pay an extra amount in addition to the amount he had borrowed. i.e, to repay the loan, the borrower has to pay the sum borrowed and the interest. Lender and Borrower The person giving the money is … Read more

Discount   The discount is referred to the reduction in the price of some commodity or service. It may anywhere appear in the distribution channel in the form of modifications in marked price (printed on the item) or in retail price (set by retailer usually by pasting a sticker on the item) or in list price (quoted for the buyer). The discount is provided … Read more

  Ratio Introduction: Ratio is the relation which one quantity bears to another of the same kind. The ratio of two quantities a and b is the fraction a/b and we write it as a: b. In the ratio a: b, we call a as the first term or antecedent and b, the second term or consequent.   … Read more

  Percentage Percent means for every 100 So, when percent is calculated for any value, it means that we calculate the value for every 100 of the reference value. percent is denoted by the symbol %. For example, x percent is denoted by x% x%=x/100 Example : 25%=25/100=1/4 To express x/y as a percent,we have x/y=(x/y×100)% Example : … Read more

Age Problems   Important Formulas on “Problems on Ages”:   If the current age is x, then ntimes the age is nx. If the current age is x, then age nyears later/hence = x+ n. If the current age is x, then age nyears ago = x– n. The ages in a ratio a: bwill be ax and bx. 5. If the current age is x, then 1 of the age is … Read more

  Pipes and Cistern   Inlet: A pipe connected with a tank or a cistern or a reservoir, that fills it, is known as an inlet.   Outlet: A pipe connected with a tank or cistern or reservoir, emptying it, is known as an outlet.   If a pipe can fill a tank in xhours, then: … Read more

  This module will teach you the basics of direct and indirect proportions. These concepts will further help you in time and work questions. Important Formulas – chain rule Direct Proportion Two quantities are said to be directly proportional, if on the increase or decrease of the one, the other increases or decreases the same … Read more

Fractions Any unit can be divided into any numbers of equal parts, one or more of this parts is called fraction of that unit. e.g. one-forth (1/4), one-third (1/3), three-seventh (3/7) etc. The lower part indicates the number of equal parts into which the unit is divided, is called denominator. The upper part, which indicates the number of … Read more