SOLUTION: "I am 3 times as old as Sue is," Frank said to Ann. "On the other hand, I am 15 years older than John, While Sue is 1 year younger than John. How old am I?"

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Question 173634: "I am 3 times as old as Sue is," Frank said to Ann. "On the other hand, I am 15 years older than John, While Sue is 1 year younger than John. How old am I?"
Found 2 solutions by Mathtut, josmiceli:
Answer by Mathtut(3670) (Show Source):
You can put this solution on YOUR website!
let ages of sue frank,ann,and john: be s,f,a,and j respectively
:
f=3s........eq 1
f=j+15......eq 2----->j=f-15
s=j-1.......eq 3
:
take f's value from eq 1 and plug it into eq 2
:
j=(3s)-15
:
now take j's value and plug it into eq 3
:
s=(3s-15)-1
:
2s=16
:

:
franks age

Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!
Let Frank's age =
Let Sue's age =
Let John's age =
Given is:
(1)
(2)
(3)
Substitute in (1) fro in (2)
(4)
Subtract (3) from (4)
(5)

Substitute this result in (1)

Now substitute in (3) to find

Frank is 24 years old
check answer:
(1)

OK
(2)

OK
(3)

OK