Jen had some pens at first. She gave 19 of her pens to her cousin and 23 of her pens to her friend. After that, her mother gave her another 10 pens. She had 24 pens in the end. How many pens did Jen have at first?
Fraction of pens left after giving to her cousin and her friend
= 1 -
19 -
23 = 1 -
19 -
69 = 1 -
79 =
29 Number of pens left after giving to her cousin and her friend = 2 u
Number of pens left after her mother gave her another 10 pens = 2 u + 10
2 u + 10 = 24
2 u = 24 - 10
2 u = 14
1 u = 14 ÷ 2 = 7
Number of pens that Jen had at first
= 9 u
= 9 x 7
= 63
Answer(s): 63
