Some stickers are packed into exactly packets of 12.
If the stickers are repacked into packets of 7,
there are 5 more packets.
- How many packets of 7 are there?
- How many stickers are there?
|
Packets of 12 |
Packets of 7 |
Number |
1 u |
1 u + 5 |
Value |
12 |
7 |
Total value |
12 u |
7 u + 35 |
(a)
Let the number of packets of 12 be 1 u.
Number of stickers if they are in packets of 12
= 12 x 1 u
= 12 u
Number of stickers if they are in packets of 7
= 7 x (1 u + 5)
= 7 u + 35
7 u + 35 = 12 u
12 u - 7 u = 35
5 u = 35
1 u = 35 ÷ 5 = 7
Number of packets of 7
= 1 u + 5
= 7 + 5
= 12
(b)
Number of stickers
= 12 u
= 12 x 7
= 84
Answer(s): (a) 12; (b) 84