Bobby and Ivan had 246 staplers together. Bobby had 18 more staplers than Ivan. Both of them sold some of their staplers. Ivan sold 10% less staplers than what Bobby sold. In the end, Ivan had half as many staplers left as Bobby. How many staplers had Bobby left?
| |
Bobby
(1) |
Ivan
(2) |
Make p the same
(2)x2 = (3) |
Comparing Bobby
and Ivan at first |
18 more |
|
|
| Before |
132 |
114 |
228 |
| Change |
- 10 u |
- 9 u |
- 18 u |
| After |
2 p |
1 p |
2 p |
Number of staplers that Ivan had at first
= (246 - 18) ÷ 2
= 228 ÷ 2
= 114
Number of staplers that Bobby had at first
= 114 + 18
= 132
Number of staplers that Ivan sold in percent
= 100% - 10%
= 90%
90% =
90100 =
910 Make p the same.
(1) = (3)
132 - 10 u = 228 - 18 u
18 u - 10 u = 228 - 132
8 u = 96
1 u = 96 ÷ 8 = 12
Number of staplers that Bobby had left
= 132 - 10 u
= 132 - 10 x 12
= 132 - 120
= 12
Answer(s): 12
