Some stickers are packed into exactly packets of 5.
If the stickers are repacked into packets of 19,
there are 3 less packets and needs 4 more stickers to make another packet.
- How many packets are there?
- How many stickers are there?
|
Packets of 5 |
Packets of 19 |
Number |
1 u |
1 u - 3 |
Value |
5 |
19 |
Total value |
5 u |
19 u - 42 |
(a)
Let the number of packets of 5 be 1 u.
Number of stickers if they are in packets of 5
= 1 u x 5
= 5 u
Number of stickers left if another packet is not packed
= 19 - 4
= 15
Number of stickers if they are in packets of 19
= 19(1 u - 3) + 15
= 19 u - 57 + 15
= 19 u - 42
5 u = 19 u - 42
19 u - 5 u = 42
14 u = 42
1 u = 42 ÷ 14 = 3
Number of packets of 5
= 1 u
= 3
(b)
Number of stickers
= 5 u
= 5 x 3
= 15
Answer(s): (a) 3; (b) 15