121
Q:

# If each side of a square is increased by 25%, find the percentage change in its area?

 A) 65.25 B) 56.25 C) 65 D) 56

Explanation:

let each side of the square be a , then area = a x a

As given that The side is increased by 25%, then

New side = $\inline \fn_jvn \small \frac{125a}{100}$ = $\inline \fn_jvn \small \frac{5a}{4}$

New area = $\inline \fn_jvn \small \left ( \frac{5a}{4} \right )^{2}$

increased area= $\inline \fn_jvn \small \frac{25a^{2}}{16}-a^{2}$

Increase %= $\inline \fn_jvn \small \frac{\left [ \frac{9a^{2}}{16} \right ]}{a^{2}}x100$ % = 56.25%

Q:

If a 36 cm thread is used to wrap a book, lengthwise twice and breadth wise once, what is the size of the book ?

 A) 288 sq.cm B) 188 sq.cm C) 144 sq.cm D) 244 sq.cm

Explanation:

Length of the thread is 36 cms.
length wise twice breath wise once then totally thrice.
so 36/3 = 12.
so length is 12 x 2 = 24 cms
breath is 12 cms
Area of the book = length x breath = 24 x 12 = 288 sq.cm

2 8
Q:

If 4 circles of equal radius are drawn with vertices of a square as the centre , the side of the square being 7 cm, find the area of the circles outside the square ?

 A) 119.21 sq cm B) 115.395 sq cm C) 104.214 sq cm D) 111.241 sq cm

Explanation:

Because each vertice of the square is the center of a circle
(1/4) part of the total area of each circle inside of the square.
(3/4) part of the total area of each circle outside of the square.
Thus total area outside the square is $\inline \fn_jvn \small 4\left ( \frac{3}{4}x\prod x3.5x3.5 \right )$ = 115.3955 sq cm.

2 29
Q:

What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad ?

 A) 844 B) 814 C) 840 D) 820

Explanation:

Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm.
Area of each tile = (41 x 41) sq.cm

Required number of tiles =1517 x 902/(41 x 41) = 814.

4 112
Q:

A rectangular grassy plot 120 m. by 60 m has a gravel path 1.5 m wide all round it on the inside. Find the cost of gravelling the path at 65 paise per sq. metre ?

 A) Rs. 345.15 B) Rs. 245.1 C) Rs. 234.18 D) Rs. 456.65

Explanation:

area of the plot = 120m x 60m = 7200 sq.m
area of plot excluding gravel = 117m x 57m = 6669 sq.m
area of gravel = 7200 sq.m - 6669 sq.m = 531 sq.m
cost of building it = 531 sq.m x 65 ps
= 34515 ps
In Rs. = 34515/100 = Rs. 345.15.

Filed Under: Area - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams , CAT
Job Role: Bank PO

3 42
Q:

The area of a square is 1024 sq.cm. What is the ratio of the length to the breadth of a rectangle whose length is twice the side of the square and breadth is 12 cm less than the side of this square ?

 A) 14:9 B) 13:12 C) 16:5 D) 17:13

Explanation:

Area of a square SxS = 1024 => S = 32 cm
Length of the rectangle = 32x2 cm = 64 cm
Breadth of the rectangle = 32 - 12 = 20 cm
Required ratio = 64 : 20 = 16 : 5