Gem had some eraser collection.
23 of them were blue and the rest were pink. She gave away 178 of the pink erasers and 20% of the blue erasers. She then had
18 of her eraser collection left. How many erasers did Gem give away?
| |
Blue |
Pink |
Total |
Total |
Before
|
2x8 =
16 u |
1x8 =
8 u |
3x8 =
24 u |
8x3 =
24 u |
Change
|
- 0.4x8 =
- 3.2 u |
- 178 |
|
- 7x3 =
- 21 u |
After
|
1.6x8 =
12.8 u |
8 u - 178 |
|
1x3 =
3 u |
The total number of erasers that Gem had at first is repeated. Make the total number of erasers at first the same. LCM 3 and 8 is 24.
Number of blue erasers that Gem gave away
= 20% x 2 u
=
20100 x 2 u
= 0.4 u
3.2 u - 178 = 21 u
21 u - 3.2 u = 178
17.8 u = 178
1 u = 178 ÷ 17.8 = 10
Number of erasers that Gem gave away
= 21 u
= 21 x 10
= 210
Answer(s): 210
