What is the area of a tringle whose sides are 7cm and 9cm ?
18 √2
42 √6
12 √2
5 √3
12 √5
Option 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 ?
1280
1345
980
1045
1386
Option 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 ?
240
340
130
145
128
Option 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 ?
9m
6m
12m
15m
17m
Option 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 ?
48cm
42cm
154cm
88cm
28cm
Option 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.
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^2
48 m^2
24 m^2
128 m^2
120 m^2
Option 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^2
240 cm^2
144 cm^2
152 cm^2
245 cm^2
Option 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 : 7
9 : 10
13 : 7
8 : 5
3 : 4
Option 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% decrease
40% increase
45% decrease
48% increase
50% decrease
Option 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%
