Question 140380
If you switch the two figures of my age, reverse their order, you'll get a third of what my age was five years ago.
:
Let x = 10's digit of the present age
Let y = units digit
:
Reverse order = one third present age - 5 yrs
10y + x = {{{1/3}}}((10x + y)-5)
:
Multiply equation by 3:
3(10y+x) = 10x + y - 5
30y + 3x = 10x + y - 5
30y - y = 10x - 3x - 5
29y = 7x - 5
Look for an integer solution to this equation (there won't be many)
y = 2
58 = 7x - 5
58 + 5 = 7x
63 = 7x
x = {{{63/7}}}
x = 9
:
Her present at is 92
:
Check solution using the statement:
"switch the two figures of my age, you'll get a third of what my age was five years ago."
29 = {{{1/3}}}(92 - 5)
29 = {{{1/3}}}87
29 = 29