SOLUTION: Mark's age next year will be three times as old as Kim's age two years ago. If their present ages add to 21, how old is each now?

Question 545486: Mark's age next year will be three times as old as Kim's age two years ago. If their present ages add to 21, how old is each now?
Answer by oberobic(2304) (Show Source): You can put this solution on YOUR website!
M + K = 21
so
M = 21-K
.
Mark's age next year: M+1
Kim's age 2 years ago: K-2
M+1 = 3*(K-2)
.
Substitute M = 21-K.
.
21-K +1 = 3K -6
28 = 4K
K = 7
.
M = 21-7
M = 14
.
Check.
M+1 =15
3(K-2) = 15
Correct.
.
Answer: Mark is 14, and Kim is 7.
.
Done.
RELATED QUESTIONS
Next year Barbara's age will be the difference between Carol's age next year and Sarah's... (answered by ikleyn,josgarithmetic)

Six years ago Jim was 5 times as old as Henry and in 6 years Jim�s age will be 3 times... (answered by Alan3354)

Six years hence a man?s age will be three times his son!s age and three years ago he was... (answered by JulietG)

Vanda’s present age is three times that of his son. Nine years ago he was five times... (answered by MathLover1)

In three more years, Danny�s father will be 2 times as old as Danny was last year. When (answered by josmiceli)

Q1: Three years ago, Mark's age was 1 year more than thrice Aaron's. Four years from... (answered by stanbon)

Kei is twice as old as Mira. In three years, the sum of their ages will be four times as... (answered by MathLover1)

1. The sum of the ages of two friends is 60. if three times the age of one friend is 9... (answered by ankor@dixie-net.com)

Kim is six years more than twice timothy's age. Two years ago,kim was three times as old... (answered by josgarithmetic)