math
posted by gary .
A. John is now 10 years older than Marcus. Three times John's age 5 years from now will be the same as five times Marcus's age 5 years ago. How old is John now?
B. In 1 year Kristen will be four times as old as Danielle. Ten years from then Kristen will only be twice as old as Danielle. How old is Kristen now?
C. A woman was 30 years old when her daughter was born.Her age is now 6 years more than three times her daughter's age. How old will the daughter be in 5 years?

1. John is now 45 years old.
45 (John)  50 X 3 = 150
35 (Marcus)  30 X 5 = 150 
thank you

john's present age is at least three times as great as his age 10 years ago. Find the greatest possible age of john at present

A.
J=10 + M
3J +5=5M5
3(10+M)+5=5M5
30+3M+5=5M5
2M=40
M=20
J=10+M=30