Some stickers are packed into exactly packets of 12.
If the stickers are repacked into packets of 9,
there are 7 more packets and 6 stickers left.
- How many packets are there?
- How many stickers are there?
|
Packets of 12 |
Packets of 9 |
Number |
1 u |
1 u + 7 |
Value |
12 |
9 |
Total value |
12 u |
9(1 u + 7) + 6 = 9 u + 69 |
(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 9
= 9 x (1 u + 7) + 6
= 9 u + 63 + 6
= 9 u + 69
12 u = 9 u + 69
12 u - 9 u = 69
3 u = 69
1 u = 69 ÷ 3 = 23
Number of packets of 12
= 1 u
= 23
(b)
Number of stickers
= 12 u
= 12 x 23
= 276
Answer(s): (a) 23; (b) 276