- What is the area of a tringle whose sides are 7cm and 9cm ?
18 √242 √612 √25 √312 √5Option E

S = 7 + 8 + 9/2 = 24/2 = 12

Area of tringle = √ S(S – a) (S – b) (S – c)

= √ 12 * 5 * 4 * 3

= 12 √ 5 - The perimeter of a square is 96 cm. If the radius of a circle is 3 cm less than the side of that square, then what is area of the circle ?
1280134598010451386Option E

perimeter of square = 96cm

side of square = 96/4 = 24cm

radius of circle = 24 – 3 = 21 cm

area of circle = πr^2 = 22/7 * 21 *21 = 1386 cm^2 - The area of a rectangular field is 252cm^2 and ratio between length and breadth is 9 :7. If cost of wire which is to be fenced is rs.2 per meter, then find cost of fencing the field ?
240340130145128Option E

Let length and breadth are 9x and 7x respectively.

9x * 7x = 252

x = 2

length = 9 * 2 = 18

breadth = 7 * 2 = 14

perimeter of rectangular field = 2(18 + 14) = 64m

cost of fencing wire = 64 * 2 = 128 - The perimeter of rectangle is 72m and ratio between the length and breadth is 11 : 7. What is the difference between the half of the length and one-seventh of the breadth of rectangle ?
9m6m12m15m17mOption A

Let length and breadth of rectangle 11x and 7x respectively.

perimeter = 72m

2(11x + 7x) = 72

x = 2

length = 11 * 2 = 22

breadth = 7 * 2 = 14

difference = 22/2 – 14 * 1/7 = 11 – 2 = 9m - There are two circle A and B and diameter of circle A is equal to be the radius of circle B,. If radius of circle A is 14 cm, Then find the difference between the perimeter of two circle ?
48cm42cm154cm88cm28cmOption D

Radius of circle A = 14 cm

Diameter of circle A = 14 * 2 = 28

radius of circle B = 28

perimeter of circle A = 2 * 22/7 * 14 = 88cm

perimeter of circle B = 2 * 22/7 * 28 = 176 cm

difference = 176 – 88 = 88cm - Curved surface area of a cylinder is 2640 cm^2 and its height is 20cm. Find the volume of a cylinder.
27720 cm^24840 cm^222350 cm^232430 cm^216340 cm^2Option A

C.S.A = 2640

2πrh = 2640

2 * 22/7 * r * 20 = 2640

r = 2640 * 7 / 44 * 20 = 21

volume = πr^2h = 22/7 * 21 * 21 * 20 = 27720 cm^2 - The length of the rectangle A is 4 m more than the breadth of rectangle and perimeter of rectangle A is 56m. What is the area of rectangle B whose length is equal to the length of rectangle A and breadth is 8 m ?
64 m^248 m^224 m^2128 m^2120 m^2Option D

Let breadth of rectangle A = x

length = x + 4

perimeter = 56

2(x + x + 4) = 56

4x + 8 = 56

x = 12

length of rectangle A = 12 + 4 = 16

length of rectangle B = 16

breadth = 8

area = 16 * 8 = 128 m^2 - A trapezium whose parallel sides are 18 cm and 14 cm long and distance between them ids 9cm. What is the area of trapezium ?
158 cm^2240 cm^2144 cm^2152 cm^2245 cm^2Option C

Area of trapezium = 1/2 * (18 + 14) * 9 = 144 cm ^2 - If the ratio of two curved surface area of two cylinder A and B are 4 : 5 and ratio of their radius is 2 : 1, then what is the ratio of their volumes ?
8 : 79 : 1013 : 78 : 53 : 4Option D

Let radius of cylinder A and B = r_1 and r_2

height cylinder A and B = h_1 and h_2

2πr_1 h_1 / 2πr_2 h_2 = 4/5

h_1 / h_2 * 2/1 = 4/5

h_1 / h_2 = 2/5

ratio of their volumes = π^2r_1 h_1 / π^2r_2 h_2

(2)^2 * 2 / (1)^2 * 5 = 8/5 - If the radius of cone is increased by 50% and height is decreased by 40%, then find the percentage change in the volume ?
55% decrease40% increase45% decrease48% increase50% decreaseOption A

Let radius of cone = 100

after increased radius of cone = 100 + 50 = 150

ratio = 2 : 3

let height of cone = 100

after decreased radius of cone = 100 – 40 = 60

ratio = 5 : 3

volume = 1/3 * πr^2h = 1/3 * 22/7 * 4 * 5 = 440 / 21

volume = 1/3 * πr^2h = 1/3 * 22/7 * 3 * 3 = 198/21

decrease = 242 / 440 * 100 = 55%