SOLUTION: Frank is 17 years old and his grandfather is 77 years old. How old will Frank's grandfather be when he is exactly 4 times as old as Frank?
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You can put this solution on YOUR website! Frank is 17 years old and his grandfather is 77 years old.
How old will Frank's grandfather be when he is exactly 4 times as old as Frank?
:
Let y = the number years later for this to be true
77 + y = 4(17 + y)
77 + y = 68 + 4y
77 - 68 = 4y - y
9 = 3y
y = 9/3
y = 3 yrs, when Grandpa will 4 times as old as Frank
:
At that time (add 3 to their ages), Grandpa will 80, and Frank will be 20
