SOLUTION: what number must be added to 100 and 20-the same to both-so that the answers are in the ratio 3:1?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: what number must be added to 100 and 20-the same to both-so that the answers are in the ratio 3:1?       Log On


   

Question 954766: what number must be added to 100 and 20-the same to both-so that the answers are in the ratio 3:1?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
(100+x)/(20+x)=3/1 Multiply each side by (20+x).
100+x=3(20+x)
100+x=60+3x Subtract (x+60) from each side.
40=2x Divide each side by 2.
20=x
ANSWER: To achieve a 3:1 ratio you must add 20 to 100 and 20.