Some stickers are packed into exactly packets of 8.
If the stickers are repacked into packets of 13,
there are 2 less packets and needs 7 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 8 |
Packets of 13 |
Number |
1 u |
1 u - 2 |
Value |
8 |
13 |
Total value |
8 u |
13 u - 20 |
(a)
Let the number of packets of 8 be 1 u.
Number of stickers if they are in packets of 8
= 1 u x 8
= 8 u
Number of stickers left if another packet is not packed
= 13 - 7
= 6
Number of stickers if they are in packets of 13
= 13(1 u - 2) + 6
= 13 u - 26 + 6
= 13 u - 20
8 u = 13 u - 20
13 u - 8 u = 20
5 u = 20
1 u = 20 ÷ 5 = 4
Number of packets of 8
= 1 u
= 4
(b)
Number of stickers
= 8 u
= 8 x 4
= 32
Answer(s): (a) 4; (b) 32