First make the denominator equal for both fractions. The LCM of 8 and 5 is 40, so 40 will be the common denominator. 3/8=15/40 and 2/5=16/40 Add them together. 15/40+16/40=31/40 He has 9/40 of his money left, which means 9/40 of the total money=$6.72 Make an equation to solve for how much money he had when he started (x). 6.72/x=9/40 After solving, x= about $29.87