Some stickers are packed into exactly packets of 10.
If the stickers are repacked into packets of 5,
there are 4 more packets.
- How many packets of 5 are there?
- How many stickers are there?
|
Packets of 10 |
Packets of 5 |
Number |
1 u |
1 u + 4 |
Value |
10 |
5 |
Total value |
10 u |
5 u + 20 |
(a)
Let the number of packets of 10 be 1 u.
Number of stickers if they are in packets of 10
= 10 x 1 u
= 10 u
Number of stickers if they are in packets of 5
= 5 x (1 u + 4)
= 5 u + 20
5 u + 20 = 10 u
10 u - 5 u = 20
5 u = 20
1 u = 20 ÷ 5 = 4
Number of packets of 5
= 1 u + 4
= 4 + 4
= 8
(b)
Number of stickers
= 10 u
= 10 x 4
= 40
Answer(s): (a) 8; (b) 40