Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 11,
there are 7 less packets and needs 8 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 11 |
Number |
1 u |
1 u - 7 |
Value |
9 |
11 |
Total value |
9 u |
11 u - 74 |
(a)
Let the number of packets of 9 be 1 u.
Number of stickers if they are in packets of 9
= 1 u x 9
= 9 u
Number of stickers left if another packet is not packed
= 11 - 8
= 3
Number of stickers if they are in packets of 11
= 11(1 u - 7) + 3
= 11 u - 77 + 3
= 11 u - 74
9 u = 11 u - 74
11 u - 9 u = 74
2 u = 74
1 u = 74 ÷ 2 = 37
Number of packets of 9
= 1 u
= 37
(b)
Number of stickers
= 9 u
= 9 x 37
= 333
Answer(s): (a) 37; (b) 333