Lucy had some pen collection.
35 of them were gold and the rest were silver. She gave away 113 of the silver pens and 50% of the gold pens. She then had
23 of her pen collection left. How many pens did Lucy give away?
| |
Gold |
Silver |
Total |
Total |
Before
|
3x3 =
9 u |
2x3 =
6 u |
5x3 =
15 u |
3x5 =
15 u |
Change
|
- 1.5x3 =
- 4.5 u |
- 113 |
|
- 1x5 =
- 5 u |
After
|
1.5x3 =
4.5 u |
6 u - 113 |
|
2x5 =
10 u |
The total number of pens that Lucy had at first is repeated. Make the total number of pens at first the same. LCM 5 and 3 is 15.
Number of gold pens that Lucy gave away
= 50% x 3 u
=
50100 x 3 u
= 1.5 u
4.5 u - 113 = 5 u
5 u - 4.5 u = 113
0.5 u = 113
1 u = 113 ÷ 0.5 = 226
Number of pens that Lucy gave away
= 5 u
= 5 x 226
= 1130
Answer(s): 1130
