Some stickers are packed into exactly packets of 7.
If the stickers are repacked into packets of 16,
there are 4 less packets and needs 6 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 7 |
Packets of 16 |
Number |
1 u |
1 u - 4 |
Value |
7 |
16 |
Total value |
7 u |
16 u - 54 |
(a)
Let the number of packets of 7 be 1 u.
Number of stickers if they are in packets of 7
= 1 u x 7
= 7 u
Number of stickers left if another packet is not packed
= 16 - 6
= 10
Number of stickers if they are in packets of 16
= 16(1 u - 4) + 10
= 16 u - 64 + 10
= 16 u - 54
7 u = 16 u - 54
16 u - 7 u = 54
9 u = 54
1 u = 54 ÷ 9 = 6
Number of packets of 7
= 1 u
= 6
(b)
Number of stickers
= 7 u
= 7 x 6
= 42
Answer(s): (a) 6; (b) 42