Yen had some pencils at first. She gave 15 of her pencils to her brother and 13 of her pencils to her buddy. After that, her mother gave her another 10 pencils. She had 66 pencils in the end. How many pencils did Yen have at first?
Fraction of pencils left after giving to her brother and her buddy
= 1 -
15 -
13 = 1 -
315 -
515 = 1 -
815 =
715 Number of pencils left after giving to her brother and her buddy = 7 u
Number of pencils left after her mother gave her another 10 pencils = 7 u + 10
7 u + 10 = 66
7 u = 66 - 10
7 u = 56
1 u = 56 ÷ 7 = 8
Number of pencils that Yen had at first
= 15 u
= 15 x 8
= 120
Answer(s): 120
