Question

A rectangular piece of iron sheet measuring 50units by 100units is rolled into a cylinder of height 50units. If the cost of painting the cylinder is 21$ per 100 square units, then what will be the cost of painting its outer surface?

Answer 1

What have you tried so far? :)

Answer 2

1050$ !!?

Answer 3

Yes, that's right!

Answer 4

As the calculated answer is not equal to other options, only option B is correct.<br>When the rectangular sheet is rolled into a cylinder of height 50 units, its length 100 units becomes the circumference of the circular edge of the cylinder.<br><img src='images5/q1_exp1.gif' width='469' height='122' >