Quantitative Aptitude :: Problems on Ages - Discussion
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When you reverse the digits of age of father you will get the age of son. one year ago the age of father was twice that of son's age. What are the current ages of father and son?
A73 & 37
B73 & 45
C65 & 37
DNone of these
Show Explanation
When you reverse the digits of age of father you will get the age of son.
10x y = father's age
10y x = son's age
:
one year ago the age of father was twice that of son's age.
10x y - 1 = 2(10y x - 1)
10x y - 1 = 20y 2x - 2
10x - 2x = 20y - y - 2 1
8x = 19y - 1
x = 19/8y - 1/8
Only one set of single digit integers will satisfy this equation
y = 3; x = 7
Current ages of father and son
Dad is 73, son is 37
Check one year ago
Dad is 72, son is 36, half Dad's age
Asked In ::
When you reverse the digits of age of father you will get the age of son.
10x y = father's age
10y x = son's age
:
one year ago the age of father was twice that of son's age.
10x y - 1 = 2(10y x - 1)
10x y - 1 = 20y 2x - 2
10x - 2x = 20y - y - 2 1
8x = 19y - 1
x = 19/8y - 1/8
Only one set of single digit integers will satisfy this equation
y = 3; x = 7
Current ages of father and son
Dad is 73, son is 37
Check one year ago
Dad is 72, son is 36, half Dad's age
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