Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 12,
there are 8 less packets and 6 stickers extra.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 12 |
Number |
1 u |
1 u - 8 |
Value |
9 |
12 |
Total value |
9 u |
12 u - 90 |
(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 if they are in packets of 12
= 12(1 u - 8) + 6
= 12 u - 96 + 6
= 12 u - 90
9 u = 12 u - 90
12 u - 9 u = 90
3 u = 90
1 u = 90 ÷ 3 = 30
Number of packets of 9
= 1 u
= 30
(b)
Number of stickers
= 9 u
= 9 x 30
= 270
Answer(s): (a) 30; (b) 270