Question 3347: 22 is 80% of what?/ 32 is whatt percent of 56?/ and if x is 8 when y is 18, and x and y vary directly, what is the value of y when x is 10? Found 2 solutions by longjonsilver, mrduffner:Answer by longjonsilver(2297) (Show Source):
You can put this solution on YOUR website! When you have a problem written out, like "22 is 80% of what", you want to look for certain words that go with an operation or math symbol. For example, when you see "is" you should immediately think "equals." When you see the word "what" you should think "variable" because it is the "what" that we are trying to find.
Let's convert this into an equation.
To make the equation in terms of X, we divide both sides by .8.
We then have our solution.
For the next problem, we need to find our percent. Let's look for our signal words again.
We divide both sides of the equation by 56 to find the solution in terms of X.
Our solution is , or %.
Finally, the last problem. This can be solved as a proportion. The whole bit about X and Y varying directly is about whether or not Y grows when X grows or if Y gets smaller as X grows. That would be a problem of inverse variation. This problem is of direct variation.
We cross multiply.
Then we divide both sides by 8.
And we have our solution.
(