First, Alvin gave Joyce and Sean 2/3 of the remainder, to solve first find the common denominator, which in this case is 24. Then, 1/3=?/24, 24/3=8 so it is 8/24 for the total given by Alvin. Joyce got 5/8, 5/8=?/24, 24/8=3,3 x 5=15, 15/24.
15/24 - 8/24= 7/24 is the answer
To start off, Chang has already saved $45. $125 - $45 = $80. Therefore, he owes $80. $80 ÷ 7 = 11.4285714286, so he needs to work 12 full hours to pay for his trip.