Bobby and Glen had 85 notebooks together. Glen had 5 less notebooks than Bobby. Both of them sold some of their notebooks. Glen sold 20% more notebooks than what Bobby sold. In the end, Glen had half as many notebooks left as Bobby. How many notebooks had Glen left?
| |
Bobby
(1) |
Glen
(2) |
Make p the same
(2)x2 = (3) |
Comparing Bobby
and Glen at first |
5 more |
|
|
| Before |
45 |
40 |
80 |
| Change |
- 5 u |
- 6 u |
- 12 u |
| After |
2 p |
1 p |
2 p |
Number of notebooks that Glen had at first
= (85 - 5) ÷ 2
= 80 ÷ 2
= 40
Number of notebooks that Bobby had at first
= 40 + 5
= 45
Number of notebooks that Glen sold in percent
= 100% + 20%
= 120%
120% =
120100 =
65 Make p the same.
(1) = (3)
45 - 5 u = 80 - 12 u
12 u - 5 u = 80 - 45
7 u = 35
1 u = 35 ÷ 7 = 5
Number of notebooks that Glen had left
= 40 - 6 u
= 40 - 6 x 5
= 40 - 30
= 10
Answer(s): 10
