Some stickers are packed into exactly packets of 8.
If the stickers are repacked into packets of 15,
there are 7 less packets.
- How many packets are there?
- How many stickers are there?
|
Packets of 8 |
Packets of 15 |
Number |
1 u |
1 u - 7 |
Value |
8 |
15 |
Total value |
8 u |
15(1 u - 7) = 15 u - 105 |
(a)
Let the number of packets of 8 be 1 u.
Number of stickers in packets of 8
= 1 u x 8
= 8 u
Number of stickers in packets of 15
= 15 x (1 u - 7)
= 15 u - 105
8 u = 15 u - 105
15 u - 8 u = 105
7 u = 105
1 u = 105 ÷ 7 = 15
Number of packets of 8 = 15
(b)
Number of stickers
= 8 u
= 8 x 15
= 120
Answer(s): (a) 15; (b) 120