Some stickers are packed into exactly packets of 7.
If the stickers are repacked into packets of 10,
there are 5 less packets and 2 stickers extra.
- How many packets are there?
- How many stickers are there?
|
Packets of 7 |
Packets of 10 |
Number |
1 u |
1 u - 5 |
Value |
7 |
10 |
Total value |
7 u |
10 u - 48 |
(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 if they are in packets of 10
= 10(1 u - 5) + 2
= 10 u - 50 + 2
= 10 u - 48
7 u = 10 u - 48
10 u - 7 u = 48
3 u = 48
1 u = 48 ÷ 3 = 16
Number of packets of 7
= 1 u
= 16
(b)
Number of stickers
= 7 u
= 7 x 16
= 112
Answer(s): (a) 16; (b) 112