Some stickers are packed into exactly packets of 8.
If the stickers are repacked into packets of 12,
there are 7 less packets and 4 stickers extra.
- How many packets are there?
- How many stickers are there?
|
Packets of 8 |
Packets of 12 |
Number |
1 u |
1 u - 7 |
Value |
8 |
12 |
Total value |
8 u |
12 u - 80 |
(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 if they are in packets of 12
= 12(1 u - 7) + 4
= 12 u - 84 + 4
= 12 u - 80
8 u = 12 u - 80
12 u - 8 u = 80
4 u = 80
1 u = 80 ÷ 4 = 20
Number of packets of 8
= 1 u
= 20
(b)
Number of stickers
= 8 u
= 8 x 20
= 160
Answer(s): (a) 20; (b) 160