Some stickers are packed into exactly packets of 5.
If the stickers are repacked into packets of 12,
there are 3 less packets and needs 4 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 5 |
Packets of 12 |
Number |
1 u |
1 u - 3 |
Value |
5 |
12 |
Total value |
5 u |
12 u - 28 |
(a)
Let the number of packets of 5 be 1 u.
Number of stickers if they are in packets of 5
= 1 u x 5
= 5 u
Number of stickers left if another packet is not packed
= 12 - 4
= 8
Number of stickers if they are in packets of 12
= 12(1 u - 3) + 8
= 12 u - 36 + 8
= 12 u - 28
5 u = 12 u - 28
12 u - 5 u = 28
7 u = 28
1 u = 28 ÷ 7 = 4
Number of packets of 5
= 1 u
= 4
(b)
Number of stickers
= 5 u
= 5 x 4
= 20
Answer(s): (a) 4; (b) 20