Some stickers are packed into exactly packets of 11.
If the stickers are repacked into packets of 7,
there are 4 more packets.
- How many packets of 7 are there?
- How many stickers are there?
|
Packets of 11 |
Packets of 7 |
Number |
1 u |
1 u + 4 |
Value |
11 |
7 |
Total value |
11 u |
7 u + 28 |
(a)
Let the number of packets of 11 be 1 u.
Number of stickers if they are in packets of 11
= 11 x 1 u
= 11 u
Number of stickers if they are in packets of 7
= 7 x (1 u + 4)
= 7 u + 28
7 u + 28 = 11 u
11 u - 7 u = 28
4 u = 28
1 u = 28 ÷ 4 = 7
Number of packets of 7
= 1 u + 4
= 7 + 4
= 11
(b)
Number of stickers
= 11 u
= 11 x 7
= 77
Answer(s): (a) 11; (b) 77