Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 16,
there are 7 less packets.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 16 |
Number |
1 u |
1 u - 7 |
Value |
9 |
16 |
Total value |
9 u |
16(1 u - 7) = 16 u - 112 |
(a)
Let the number of packets of 9 be 1 u.
Number of stickers in packets of 9
= 1 u x 9
= 9 u
Number of stickers in packets of 16
= 16 x (1 u - 7)
= 16 u - 112
9 u = 16 u - 112
16 u - 9 u = 112
7 u = 112
1 u = 112 ÷ 7 = 16
Number of packets of 9 = 16
(b)
Number of stickers
= 9 u
= 9 x 16
= 144
Answer(s): (a) 16; (b) 144