Cathy had some chocolate bars. She sold 30% of her chocolate bars and gave half of the remainder to her brother. After that, she bought 45 chocolate bars and had a total of 101 chocolate bars in the end. How many chocolate bars did Cathy have at first?
Percentage of chocolate bars that Cathy left after selling 305 of her chocolate bars
= 100% - 30%
= 70%

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

Number of chocolate bars that Cathy had left = 7 u

Number of chocolate bars that Cathy had in the end = 7 u + 45

7 u + 45 = 101
7 u = 101 - 45
7 u = 56

1 u = 56 ÷ 7 = 8

Total number of chocolate bars that Cathy had at first
= 20 u
= 20 x 8
= 160

Answer(s): 160