Vanessa had some pen collection.
12 of them were pink and the rest were purple. She gave away 135 of the purple pens and 30% of the pink pens. She then had
25 of her pen collection left. How many pens did Vanessa give away?
|
Pink |
Purple |
Total |
Total |
Before
|
1x5 = 5 u |
1x5 = 5 u |
2x5 = 10 u |
5x2 = 10 u |
Change
|
- 0.3x5 = - 1.5 u |
- 135 |
|
- 3x2 = - 6 u |
After
|
0.7x5 = 3.5 u |
5 u - 135 |
|
2x2 = 4 u |
The total number of pens that Vanessa had at first is repeated. Make the total number of pens at first the same. LCM 2 and 5 is 10.
Number of pink pens that Vanessa gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
1.5 u - 135 = 6 u
6 u - 1.5 u = 135
4.5 u = 135
1 u = 135 ÷ 4.5 = 30
Number of pens that Vanessa gave away
= 6 u
= 6 x 30
= 180
Answer(s): 180