SOLUTION: A is 27 years old. B is one third older. How many years ago was the ratio of A's age to B's age equal to 4:7?

Algebra.Com
Question 732023:
A is 27 years old. B is one third older. How many years ago was the ratio of A's age to B's age equal to 4:7?

Answer by checkley79(3341)   (Show Source): You can put this solution on YOUR website!
4/7=(A-X)/(B-X)
4/7=(27-X)/(27+9-X) CROSS MULTIPLY.
7(27-X)=4(36-X)
189-7X=144-4X
-7X+4X=144-189
-3X=-45
X=-45/-3
X=15 YEARS AGE THEIR AGES WERE 4:7
PROOF:
(27-15)/(36-15)
12/21=4/7
12*7=21*4
84=84

RELATED QUESTIONS

Eighteen years ago the ratio of As age to B s age was 8:13. Their present ratios are 5:7. (answered by ankor@dixie-net.com)
The ratio of Kawika’s age to Tony’s age is 3:4. Two years ago, their average age was... (answered by MathLover1,Alan3354,MathTherapy)
Tom is y years old. (a) how old was he 3 years ago? (b) how old will she be in 4 years... (answered by hamsanash1981@gmail.com)
Jane is y years old a) how old was she 3 years ago? b) how old will she be in 4 years... (answered by josgarithmetic)
Sophia`s father age is two years older than her mother. Presently, Sophia`s age is 1/4 of (answered by Timnewman)
A man is now 55 years old, and his wife is 45 years old. How many years ago was the ratio (answered by josmiceli)
ratio of A's age to B's age is equal to 4 :3. A will be 26 years old after 6 years how... (answered by RedemptiveMath)
a half of what John's age was 4 years ago is equal to one third of what it will be in 5... (answered by xcentaur)
Three years ago, my age was a prime number. • This year, my age is a multiple of 4. (answered by Edwin McCravy)