Some stickers are packed into exactly packets of 11.
If the stickers are repacked into packets of 9,
there are 7 more packets and 5 stickers left.
- How many packets are there?
- How many stickers are there?
|
Packets of 11 |
Packets of 9 |
Number |
1 u |
1 u + 7 |
Value |
11 |
9 |
Total value |
11 u |
9(1 u + 7) + 5 = 9 u + 68 |
(a)
Let the number of packets of 11 be 1 u.
Number of stickers if they are in packets of 11
= 1 u x 11
= 11 u
Number of stickers if they are in packets of 9
= 9 x (1 u + 7) + 5
= 9 u + 63 + 5
= 9 u + 68
11 u = 9 u + 68
11 u - 9 u = 68
2 u = 68
1 u = 68 ÷ 2 = 34
Number of packets of 11
= 1 u
= 34
(b)
Number of stickers
= 11 u
= 11 x 34
= 374
Answer(s): (a) 34; (b) 374