David and Liam had 63 pencils together. Liam had 5 less pencils than David. Both of them sold some of their pencils. Liam sold 10% more pencils than what David sold. In the end, Liam had half as many pencils left as David. How many pencils had Liam left?
| |
David
(1) |
Liam
(2) |
Make p the same
(2)x2 = (3) |
Comparing David
and Liam at first |
5 more |
|
|
| Before |
34 |
29 |
58 |
| Change |
- 10 u |
- 11 u |
- 22 u |
| After |
2 p |
1 p |
2 p |
Number of pencils that Liam had at first
= (63 - 5) ÷ 2
= 58 ÷ 2
= 29
Number of pencils that David had at first
= 29 + 5
= 34
Number of pencils that Liam sold in percent
= 100% + 10%
= 110%
110% =
110100 =
1110 Make p the same.
(1) = (3)
34 - 10 u = 58 - 22 u
22 u - 10 u = 58 - 34
12 u = 24
1 u = 24 ÷ 12 = 2
Number of pencils that Liam had left
= 29 - 11 u
= 29 - 11 x 2
= 29 - 22
= 7
Answer(s): 7
