It is -16. Get b/a and then plug that answer.
Your question is not clearly stated. Do you mean the difference between 10 * 10 * x, and 7 * 7 * 7 *x ? Then the number is x = 119/243. That's about 0.48971... in decimal form.
It's confusing when you say the "difference of a number". Differences are BETWEEN two numbers. See what I mean?
Answer:
15 cm
Step-by-step explanation:
When the rectangular sheet rolled along its length, the breadth becomes the height of the cylinder, and the length becomes the circle, so the height is 15 cm