SOLUTION: Margo is currently twice as old as Joy was three decades ago, and Joy is currently three times as old as Margo was two decades ago. How old was Joy when Margo was born?

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Question 1002432: Margo is currently twice as old as Joy was three decades ago, and Joy is currently three times as old as Margo was two decades ago. How old was Joy when Margo was born?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Margo is currently twice as old as Joy was three decades ago,
m = 2(j-30)
m = 2j - 60
and Joy is currently three times as old as Margo was two decades ago.
j = 3(m-20)
j = 3m - 60
replace m with (2j-60), from the 1st statement
j = 3(2j-60) - 60
j = 6j - 180 - 60
j = 6j - 240
240 = 6j - j
240 = 5j
j = 240/5
j = 48 yrs is Joy
Find Margo's age
m = 2(48) - 60
m = 96 - 60
m = 36 yrs
:
:
Check this in the 2nd statement
j = 3(m-20)
48 = 3(36 - 20)
48 = 3(16)
:
How old was Joy when Margo was born?
48 - 36 = 12 yrs old