Ivan and Gabriel had 105 pens together. Gabriel had 3 less pens than Ivan. Both of them sold some of their pens. Gabriel sold 30% more pens than what Ivan sold. In the end, Gabriel had half as many pens left as Ivan. How many pens had Gabriel left?
| |
Ivan
(1) |
Gabriel
(2) |
Make p the same
(2)x2 = (3) |
Comparing Ivan
and Gabriel at first |
3 more |
|
|
| Before |
54 |
51 |
102 |
| Change |
- 10 u |
- 13 u |
- 26 u |
| After |
2 p |
1 p |
2 p |
Number of pens that Gabriel had at first
= (105 - 3) ÷ 2
= 102 ÷ 2
= 51
Number of pens that Ivan had at first
= 51 + 3
= 54
Number of pens that Gabriel sold in percent
= 100% + 30%
= 130%
130% =
130100 =
1310 Make p the same.
(1) = (3)
54 - 10 u = 102 - 26 u
26 u - 10 u = 102 - 54
16 u = 48
1 u = 48 ÷ 16 = 3
Number of pens that Gabriel had left
= 51 - 13 u
= 51 - 13 x 3
= 51 - 39
= 12
Answer(s): 12
