Some stickers are packed into exactly packets of 12.
If the stickers are repacked into packets of 7,
there are 4 more packets and 2 stickers left.
- How many packets are there?
- How many stickers are there?
|
Packets of 12 |
Packets of 7 |
Number |
1 u |
1 u + 4 |
Value |
12 |
7 |
Total value |
12 u |
7(1 u + 4) + 2 = 7 u + 30 |
(a)
Let the number of packets of 12 be 1 u.
Number of stickers if they are in packets of 12
= 1 u x 12
= 12 u
Number of stickers if they are in packets of 7
= 7 x (1 u + 4) + 2
= 7 u + 28 + 2
= 7 u + 30
12 u = 7 u + 30
12 u - 7 u = 30
5 u = 30
1 u = 30 ÷ 5 = 6
Number of packets of 12
= 1 u
= 6
(b)
Number of stickers
= 12 u
= 12 x 6
= 72
Answer(s): (a) 6; (b) 72