Question

Answer all the questions.

21. The volume of the cylinder is 660 sq. cm. find the height if its radius is 5 cm.

22. The total surface area of the cube is 54 sq.cm. What is the length of its sides.

23. Find the area of the trapezium if lengths of its parallel sides are 8 cm and 10

cm and height is 7 cm.

24. The area of the rhombus is 50 sq.cm. and one of its diagonals is 15 cm. Find

the other diagonal.

25. If d varies directly as t, and if d = 4 when t = 9, find d when t = 21.

26. Factorize 10pq – 3rq – 10ps + 3rs.

27. Factorize x2 + 7x + 12.​

Answer 1

21: the vole of cylinder is = 660

radius of cylinder is 5 cm

660= 22/7×5×5×h

660×7/22×5×5= h

the hight is 8.4 cm

22: total surface area = 54 cm^2

6(a)^2 =54/6

a=√9

a = 3 cm

23: 45 sq. cm

1212 x h x (a + b) = 1212 x 5 x (10 + 8) = 45

24: A=pq / 2

Solving form

p=2A

q=2·50/ 15

≈6.66667cm

25: let d = kd

4=k *9

k = 4/9

thus

d= 4/9 * 21

=28/3

26: 10 pq - 3qr -10 ps +3 rs

10 pq- 10 ps -3 qr +3 rs

10 p(q-s) -3r ( q-s )

(q-s)(10p-3s)

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