he saves $860 per month
calculate each of his outgoings
rent = [tex]\frac{1}{4}[/tex] × $3600 = [tex]\frac{3600}{4}[/tex] = $900
food = [tex]\frac{2}{5}[/tex] × $3600 = [tex]\frac{2(3600)}{5}[/tex] = $1440
activities = [tex]\frac{1}{9}[/tex] × $3600 = [tex]\frac{3600}{9}[/tex] = $400
savings = $3600 - ( 900 + 1440 + 400 ) = $860
To add the fractions we must make the denominators = 180.
45/180 + 72/180 + 20/180 = 137/180
Expense Total = (137/180) * 3,600 = $2,740
Savings Total = (180 - 137) / 180
Savings = (43/180) * 3,600
Savings = $860
***********DOUBLE CHECK**********************
1/4=.25 2/5 = .40 1/9 = .111111
.25 + .40 + .111111 = .761111
Expenses = .761111 * 3,600 = 2,740.00
Savings = 3,600 - 2,740.00 = 860.00
