Some stickers are packed into exactly packets of 12.
If the stickers are repacked into packets of 9,
there are 4 more packets and 3 stickers left.
- How many packets are there?
- How many stickers are there?
|
Packets of 12 |
Packets of 9 |
Number |
1 u |
1 u + 4 |
Value |
12 |
9 |
Total value |
12 u |
9(1 u + 4) + 3 = 9 u + 39 |
(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 + 4) + 3
= 9 u + 36 + 3
= 9 u + 39
12 u = 9 u + 39
12 u - 9 u = 39
3 u = 39
1 u = 39 ÷ 3 = 13
Number of packets of 12
= 1 u
= 13
(b)
Number of stickers
= 12 u
= 12 x 13
= 156
Answer(s): (a) 13; (b) 156