143
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:

Calculate the number of bricks, each measuring 25 cm x 15 cm x 8 cm required to construct a wall of dimensions 10 m x 4 cm x 6 m when 10% of its volume is occupied by mortar  ?

 A) 720 B) 600 C) 660 D) 6000

Explanation:

Let the number of bricks be 'N'

10 x 4/100 x 6 x 90/100 = 25/100 x 15/100 x 8/100 x N

10 x 4 x 6 x 90 = 15 x 2 x N => N = 720.

4 90
Q:

If the sides of a triangle are 26 cm, 24 cm and 10 cm, what is its area ?

 A) 108 sq.cm B) 112 sq.cm C) 116 sq.cm D) 120 sq.cm

Explanation:

The triangle with sides 26 cm, 24 cm and 10 cm is right angled, where the hypotenuse is 26 cm.

Area of the triangle =1/2 x base x height => 1/2 x 24 x 10 = 120 sq.cm

3 213
Q:

An order was placed for the supply of a carpet whose breadth was 6 m and length was 1.44 times the breadth. What be the cost of a carpet whose length and breadth are 40% more and 25% more respectively than the first carpet. Given that the ratio of carpet is Rs. 45 per sq. m ?

 A) Rs. 4082.40 B) Rs. 1024.21 C) Rs. 2810.6 D) Rs. 3214

Explanation:

Length of the first carpet = (1.44)(6) = 8.64 cm

Area of the second carpet = 8.64(1 + 40/100) 6 (1 + 25/100)

= 51.84(1.4)(5/4) sq m = (12.96)(7) sq m

Cost of the second carpet = (45)(12.96 x 7) = 315 (13 - 0.04) = 4095 - 12.6 = Rs. 4082.40

3 136
Q:

What is the length of the longest pole which can be kept in a room 12 m long, 4 m broad and 3 m high  ?

 A) 13 m B) 14 m C) 15 m D) 16 m

Explanation:

the length of the longest pole which can be kept in a room 12 m long, 4 m broad and 3 m high is

=> $\inline \fn_jvn \small d^{2}=12^{2}+4^{2}+3^{2} = 13$ mts.

3 256
Q:

A class is 6 meters 24 centimeters in length and 4 meters 32 centimeters in width. Find the least number of square tiles of equal size required to cover the entire floor of the class room ?

 A) 115 B) 117 C) 116 D) 114