Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 16,
there are 2 less packets and needs 5 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 16 |
Number |
1 u |
1 u - 2 |
Value |
9 |
16 |
Total value |
9 u |
16 u - 21 |
(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
= 16 - 5
= 11
Number of stickers if they are in packets of 16
= 16(1 u - 2) + 11
= 16 u - 32 + 11
= 16 u - 21
9 u = 16 u - 21
16 u - 9 u = 21
7 u = 21
1 u = 21 ÷ 7 = 3
Number of packets of 9
= 1 u
= 3
(b)
Number of stickers
= 9 u
= 9 x 3
= 27
Answer(s): (a) 3; (b) 27