Given
The monthly salary of a person $$ = Rs. 12,000 $$
Monthly expenditure $$ = Rs. 8,500 $$
Savings = salary - expenditure
Savings $$ = 12 , 000 - 8,500 $$
$$ = 3,500 $$
The ratio between expenditure and savings will be as given below
$$ 8500 : 3500 = 8500 / 3500 $$
On simplification , we get
$$ = \dfrac{85}{35} $$
$$ = \dfrac{17}{7} $$
$$ = 17 : 7 $$
$$ \therefore \, $$ The ratio between expenditure and savings will be $$ 17 : 7 $$