SOLUTION: Translate to a proportion and solve.(round to the nearest hundreth if need) (1) what number is 15% of 135 (2) 3 is what percent of 87? (3) 19.6 is 28% p

Algebra ->  Proportions  -> Lessons -> SOLUTION: Translate to a proportion and solve.(round to the nearest hundreth if need) (1) what number is 15% of 135 (2) 3 is what percent of 87? (3) 19.6 is 28% p      Log On


   

Question 34703: Translate to a proportion and solve.(round to the nearest hundreth if need)


(1) what number is 15% of 135


(2) 3 is what percent of 87?

(3) 19.6 is 28% percent of what number?
Answer by Cintchr(481) About Me  (Show Source):
You can put this solution on YOUR website!
Here is a good formula for ALL percentage problems like these:
+is%2Fof+=+percent%2F100+
Using this ... let's solve:

(1) what number is 15% of 135
+x%2F135+=+15%2F100+
Cross multiply ...
+100x+=+135%2815%29+
divide by 100
+x+=+%28135%2815%29%29%2F100+
Reduce and Multiply and divide
+x+=+%28135%283%29%29%2F20+
+x+=+%2827%283%29%29%2F4+
+x+=+81%2F4+
+x+=+20.25+

(2) 3 is what percent of 87?
+3%2F87+=+x%2F100+
+87x+=+3%28100%29+
+x+=+%283%28100%29%29%2F87+
+x+=+300%2F87+
+x+=+3.45+rounded+

(3) 19.6 is 28% percent of what number?
+19.6%2Fx+=+28%2F100+
+19.6%2Fx+=+7%2F25+
+7x+=+25%2819.6%29+
+x+=+%2825%2819.6%29%29%2F7+
+x+=+490%2F7+
+x+=+70+