Jane had some pen collection.
13 of them were gold and the rest were pink. She gave away 129 of the pink pens and 30% of the gold pens. She then had
27 of her pen collection left. How many pens did Jane give away?
| |
Gold |
Pink |
Total |
Total |
Before
|
1x7 =
7 u |
2x7 =
14 u |
3x7 =
21 u |
7x3 =
21 u |
Change
|
- 0.3x7 =
- 2.1 u |
- 129 |
|
- 5x3 =
- 15 u |
After
|
0.7x7 =
4.9 u |
14 u - 129 |
|
2x3 =
6 u |
The total number of pens that Jane had at first is repeated. Make the total number of pens at first the same. LCM 3 and 7 is 21.
Number of gold pens that Jane gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
2.1 u - 129 = 15 u
15 u - 2.1 u = 129
12.9 u = 129
1 u = 129 ÷ 12.9 = 10
Number of pens that Jane gave away
= 15 u
= 15 x 10
= 150
Answer(s): 150
