Question

A blacksmith have big iron ball of diameter

36cm. He first formed four identical

cylindrical rod out of this ball for some

construction work. When he finished his

work with the cylindrical rod, he again

mixed all the iron rod and formed some

identical small balls, each of radius 9cm.

(i)

When one solid is converted to

another solid shape, their-

(i) Surface area remain same

(ii) Volume remain same

Which of the above options is/are true:

(a) Only (i)

(b) Only (ii)

(c) Both (i) and (ii)

(d) None of them.
(ii)

If the diameter of each cylinder

formed by him is 12cm, then height

of each of them is-

(a) 54cm

(b) 36cm

(c) 45cm

(d) 72cm
(iii)

The number of small balls formed by the

blacksmith?

(a) 6

(b) 10

(c) 8

(d) 16
(iv)

What is the cost price of steel coating of a

cylindrical iron rod at the rate of Rs.3.5per

100cm2

?

(a) Rs.79.20

(b) Rs.89.20

(c) Rs.85.56

(d) Rs.71.28​

Answer 1

Answer:

a) option B

b) option C are the correct answer