Mensuration is the science of measuring the area and the volume of geometrical shapes. We have all studied mensuration at our school and we know the basic formulas of finding the volume and area of basic shapes such as square, rectangles and circles. But, it is often seen that a lot of candidates find it tough to answer IBPS RRB Mensuration Questions. The reason for this is simple. Knowing the formulas isn’t enough to solve questions in the RRB exam. You need to know how to use them in the right way. Here, we are going to take a look at the mensuration questions in general and how to solve some of the most common types of questions.

## Understanding IBPS RRB Mensuration Questions

If you are serious about clearing IBPS RRB 2021, then it goes without saying that you should prepare well for IBPS RRB mensuration questions. But what should you study and how should you study? Let us try to find answers to questions like these by looking some of the facts about the topic

### How Many Questions Come Every Year?

Questions on mensuration are quite common in the numerical ability paper in IBPS RRB Mains. Although the number of questions vary, but on an average at least 5 to 9 questions come in the exam. In IBPS RRB 2021, you can at least expect 4 to 5 questions from this section. This shows how important this particular section is.

### How difficult are the Questions?

Well, to be honest, the questions on mensuration are indeed quite difficult. The trickiest part is applying formulas for solving the questions. This comes through practice and solving as many questions as you can.

### How much should I practice?

Mensuration needs some serious practice. The first part is to memorize all the important formulas. There is no getting away from that! The next part is applying those formulas to solve the questions. For this you need to solve mock tests. Try to solve mock tests of IBPS PO, SBI PO and other such banking exams as they have a similar pattern compared to IBPS RRB exam.

## Solving IBPS RRB Mensuration Questions

Let us take a look at some common examples and see how you can solve them effectively.

Example 1: A cow is tied with a rope to a pole in the middle of a field. The length of the rope is 14m. If the cow grazes an area of 100 sqm every day, find the time taken to graze the whole field,

Solution: The rope of the cow forms the radius of a circle as the arrangement looks something like this:

Area= Π(14)2

So, the number of days is = Π(14)2/100 =6 days

Example 2: If the length of a rectangle is increased by 60%, find by what percentage the breadth must be decreased so as to maintain the same area?

Solution: In such cases, you must use the following formula:

%decrease in breadth = [%change in L{100/(100+%change in L)}]

So, here

So, the breadth should be decreased by 37.5%

Example 3: The circumference of a circle is 100cm. Find the side of the square inscribed within the circle

Solution: A square inscribed in a circle, looks something like this:

To solve such questions, use the formula

Side of the square=x

Now, we know the diagonal of the square is =x√2

In this case, diagonal is also the circumference of the circle. So, we have

100=x√2

or, x = 100/√2

or x = 70.42

These were some of the most common IBPS RRB mensuration questions. Now, let us take a look at some practice questions.

## Practice Questions

Question 1: A square with side length 4 is inscribed in a circle. What is the area of the circle?

Options:

A) 4Π

B)8Π

C)12Π

D)16Π

Question 2: A cow is tied to the corner of a rectangular plot with a 14m long rope. Find the area which the cow can graze?

Options:

A) 100 sqm

B) 140 sqm

C) 154 sqm

D) 167 sqm

Question 3: If the length of a rectangular plot is increased by 10% and the breadth is decreased by 12%. Find the % change in the area

Options:

A) +3.2%

B)-6.4%

C) +6.4%

D) -3.2%