SOLUTION: How do I find c when only a and b are provided? example: 28 is 40% of what number? The answer is 70 but what is the rule for a problem like this? Pleeease help!

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Question 596842: How do I find c when only a and b are provided?
example:
28 is 40% of what number?
The answer is 70 but what is the rule for a problem like this?
Pleeease help!
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
28 is 40% of a number (x), so we have

28 = .4x (when you see "of" you generally multiply).

Dividing both sides by .4 we obtain x = 28/.4 = 70.