Winnie had some chocolate bars. She sold 30% of her chocolate bars and gave half of the remainder to her brother. After that, she bought 16 chocolate bars and had a total of 79 chocolate bars in the end. How many chocolate bars did Winnie have at first?
Percentage of chocolate bars that Winnie left after selling 305 of her chocolate bars
= 100% - 30%
= 70%

Fraction of chocolate bars that Winnie had left after giving to her brother
= ¹₂ x 70%
= ⁷₂₀

Number of chocolate bars that Winnie had left = 7 u

Number of chocolate bars that Winnie had in the end = 7 u + 16

7 u + 16 = 79
7 u = 79 - 16
7 u = 63

1 u = 63 ÷ 7 = 9

Total number of chocolate bars that Winnie had at first
= 20 u
= 20 x 9
= 180

Answer(s): 180