Jaslyn had some chocolate bars. She sold 20% of her chocolate bars and gave half of the remainder to her brother. After that, she bought 30 chocolate bars and had a total of 34 chocolate bars in the end. How many chocolate bars did Jaslyn have at first?
Percentage of chocolate bars that Jaslyn left after selling 205 of her chocolate bars
= 100% - 20%
= 80%

Fraction of chocolate bars that Jaslyn had left after giving to her brother
= ¹₂ x 80%
= ²₅

Number of chocolate bars that Jaslyn had left = 2 u

Number of chocolate bars that Jaslyn had in the end = 2 u + 30

2 u + 30 = 34
2 u = 34 - 30
2 u = 4

1 u = 4 ÷ 2 = 2

Total number of chocolate bars that Jaslyn had at first
= 5 u
= 5 x 2
= 10

Answer(s): 10