Abi and Jean have some puffs each. If Abi gives Jean 13 puffs, Abi will have
89 as many puffs as Jean. If Abi gives Jean 11 puffs, they will have an equal number of puffs. How many puffs does Abi have at first?
| |
Case 1 |
Case 2 |
| |
Abi |
Jean |
Abi |
Jean |
| Before |
8 u + 13 |
9 u - 13 |
8.5 u + 11 |
8.5 u - 11 |
| Change |
- 13 |
+ 13 |
- 11 |
+ 11 |
| After |
8 u |
9 u |
8.5 u |
8.5 u |
Total number of puffs that Abi and Jean have
= 8 u + 9 u
= 17 u
Number of puffs that Abi and Jean each has in the end is the same.
Number of puffs that Abi and Jean each has in the end in Case 2
= 17 u ÷ 2
= 8.5 u
Number of puffs that Abi had at first is the same in Case 1 and Case 2.
8.5 u + 11 = 8 u + 13
8.5 u - 8 u = 13 - 11
0.5 u = 2
1 u = 2 ÷ 0.5 = 4
Number of puffs that Abi has
= 8 u + 13
= 8 x 4 + 13
= 32 + 13
= 45
Answer(s): 45
