Kwai Fang had some boxes of fruits for sale. She sold 35 boxes on Monday. She sold 1/5 of the remaining boxes of fruits on Tuesday. Then she had 1/3 of the total number of boxes of fruits left. How many boxes of fruits did she have at first?

Sagot :

Let total boxes : x
boxes of fruits sold on Monday : 35
boxes of fruits sold on Tuesday :  1/5 (x/35) or [tex] \frac{x}{5} [/tex] - 7
boxes of fruits left:  1/3 of x 

35 + x/5 - 7 + x/3 = x

LCD:  (5) (3)

35 (5)(3) + x(3)  - 7(3)(5) + x(5) = x (5)(3)

35 (15) + 3x - 7(15) + 5x = 15x
525 - 105 + 3x + 5x = 15x
420 = 15x - 8x

420/7 = 7x/7

x = 60 boxes total number of boxes she had at first (Final answer)

To check 
35 + 1/5(60-35) + 1/3(60) = 60

35 + 1/5(25) + 20 = 60
35 + 5 + 20 = 60
              60 = 60