Ivan and Will had 153 notebooks together. Will had 3 less notebooks than Ivan. Both of them sold some of their notebooks. Will sold 10% more notebooks than what Ivan sold. In the end, Will had half as many notebooks left as Ivan. How many notebooks had Will left?
| |
Ivan
(1) |
Will
(2) |
Make p the same
(2)x2 = (3) |
Comparing Ivan
and Will at first |
3 more |
|
|
| Before |
78 |
75 |
150 |
| Change |
- 10 u |
- 11 u |
- 22 u |
| After |
2 p |
1 p |
2 p |
Number of notebooks that Will had at first
= (153 - 3) ÷ 2
= 150 ÷ 2
= 75
Number of notebooks that Ivan had at first
= 75 + 3
= 78
Number of notebooks that Will sold in percent
= 100% + 10%
= 110%
110% =
110100 =
1110 Make p the same.
(1) = (3)
78 - 10 u = 150 - 22 u
22 u - 10 u = 150 - 78
12 u = 72
1 u = 72 ÷ 12 = 6
Number of notebooks that Will had left
= 75 - 11 u
= 75 - 11 x 6
= 75 - 66
= 9
Answer(s): 9
