SOLUTION: Beth's mom is 6 times older than Beth. Beth's dad is 7 years older than Beth's mom. The sum of their ages is 72. How old are each of them?

Question 620614: Beth's mom is 6 times older than Beth. Beth's dad is 7 years older than Beth's mom. The sum of their ages is 72. How old are each of them?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
let b = Beth's age
let m = Mom's age
let d = Dad's age
:
Write an equation for each statement. Arrange to get b and d in terms of m:
;
"Beth's mom is 6 times older than Beth."
m = 6b
or
b = m
:
"Beth's dad is 7 years older than Beth's mom."
d = m + 7
:
"The sum of their ages is 72."
b + m + d = 72
Replace b and d
(m) + m + (m+7) = 72
(m) + 2m = 72 - 7
(m) + 2m = 65
multiply equation by 6, results
m + 6(2m) = 6(65)
13m = 390
m = 390/13
m = 30 yrs is Mom's age
then
b = *30
b = 5 yrs is Beth's age
and
d = 30 + 7
d = 37 yrs is Dad's age
:
:
Check this, find the total
5 + 30 + 37 = 72

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