Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 17,
there are 4 less packets and needs 5 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 17 |
Number |
1 u |
1 u - 4 |
Value |
9 |
17 |
Total value |
9 u |
17 u - 56 |
(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
= 17 - 5
= 12
Number of stickers if they are in packets of 17
= 17(1 u - 4) + 12
= 17 u - 68 + 12
= 17 u - 56
9 u = 17 u - 56
17 u - 9 u = 56
8 u = 56
1 u = 56 ÷ 8 = 7
Number of packets of 9
= 1 u
= 7
(b)
Number of stickers
= 9 u
= 9 x 7
= 63
Answer(s): (a) 7; (b) 63