Some stickers are packed into exactly packets of 7.
If the stickers are repacked into packets of 10,
there are 6 less packets.
- How many packets are there?
- How many stickers are there?
|
Packets of 7 |
Packets of 10 |
Number |
1 u |
1 u - 6 |
Value |
7 |
10 |
Total value |
7 u |
10(1 u - 6) = 10 u - 60 |
(a)
Let the number of packets of 7 be 1 u.
Number of stickers in packets of 7
= 1 u x 7
= 7 u
Number of stickers in packets of 10
= 10 x (1 u - 6)
= 10 u - 60
7 u = 10 u - 60
10 u - 7 u = 60
3 u = 60
1 u = 60 ÷ 3 = 20
Number of packets of 7 = 20
(b)
Number of stickers
= 7 u
= 7 x 20
= 140
Answer(s): (a) 20; (b) 140