The number of purple grapes is the same as the number of red grapes in a bag. After removing
15 of the grapes, there were 31 purple grapes and 77 red grapes left in the bag. Then, another 39 purple grapes and 39 red grapes were removed and there were
29 of the grapes left in the end. How many purple grapes were removed altogether?
| |
Purple Grapes |
Red Grapes |
Total |
| Before |
1 p
67.5 |
1 p
67.5 |
9 u |
| Change 1 |
- ? (15 of the total) |
- 7 u |
| After 1 |
31 |
77 |
| Change 2 |
- 39 |
- 39 |
| After 2 |
30 |
2 u |
Number of grapes left
= 31 + 77 - 39 - 39
= 30
2 u = 30
1 u = 30 ÷ 2 = 15
Total number of grapes at first
= 9 u
= 9 x 15
= 135
Number of purple grapes at first
= 135 ÷ 2
= 67.5
Number of purple grapes removed at first
= 67.5 - 31
= 36.5
Total number of purple grapes removed
= 36.5 + 39
= 75.5
Answer(s): 75.5
