Some stickers are packed into exactly packets of 7.
If the stickers are repacked into packets of 14,
there are 2 less packets.
- How many packets are there?
- How many stickers are there?
|
Packets of 7 |
Packets of 14 |
Number |
1 u |
1 u - 2 |
Value |
7 |
14 |
Total value |
7 u |
14(1 u - 2) = 14 u - 28 |
(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 14
= 14 x (1 u - 2)
= 14 u - 28
7 u = 14 u - 28
14 u - 7 u = 28
7 u = 28
1 u = 28 ÷ 7 = 4
Number of packets of 7 = 4
(b)
Number of stickers
= 7 u
= 7 x 4
= 28
Answer(s): (a) 4; (b) 28