Some stickers are packed into exactly packets of 5.
If the stickers are repacked into packets of 10,
there are 3 less packets.
- How many packets are there?
- How many stickers are there?
|
Packets of 5 |
Packets of 10 |
Number |
1 u |
1 u - 3 |
Value |
5 |
10 |
Total value |
5 u |
10(1 u - 3) = 10 u - 30 |
(a)
Let the number of packets of 5 be 1 u.
Number of stickers in packets of 5
= 1 u x 5
= 5 u
Number of stickers in packets of 10
= 10 x (1 u - 3)
= 10 u - 30
5 u = 10 u - 30
10 u - 5 u = 30
5 u = 30
1 u = 30 ÷ 5 = 6
Number of packets of 5 = 6
(b)
Number of stickers
= 5 u
= 5 x 6
= 30
Answer(s): (a) 6; (b) 30