Question

Mary is younger than her husband, but
their ages contain the same two digits. The
sum of their ages is 11 times the difference
of their ages. How old is Mary?

Answer 1

45

Answer 2

mary is 45
her husband is 54
45+54 =99
54-45 = 9
45+54 = 11(54-45)

Answer 3

Correct.

Answer 4

how did you solve that?

Answer 5

mary's age =x
her husband's age =y
x+y = 11(y-x)
x+y = 11y-11x
12x=10y
6x=5y
since x&y are integers
y is divisible by 6 and x is divisible by 5
so the one's digit in x is 5
this means that the ten's digit in y is 5
and y must be divisible by 6
so y=54
thus x=45