Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 13,
there are 3 less packets and needs 6 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 13 |
Number |
1 u |
1 u - 3 |
Value |
9 |
13 |
Total value |
9 u |
13 u - 32 |
(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
= 13 - 6
= 7
Number of stickers if they are in packets of 13
= 13(1 u - 3) + 7
= 13 u - 39 + 7
= 13 u - 32
9 u = 13 u - 32
13 u - 9 u = 32
4 u = 32
1 u = 32 ÷ 4 = 8
Number of packets of 9
= 1 u
= 8
(b)
Number of stickers
= 9 u
= 9 x 8
= 72
Answer(s): (a) 8; (b) 72