Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 11,
there are 2 less packets.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 11 |
Number |
1 u |
1 u - 2 |
Value |
9 |
11 |
Total value |
9 u |
11(1 u - 2) = 11 u - 22 |
(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 11
= 11 x (1 u - 2)
= 11 u - 22
9 u = 11 u - 22
11 u - 9 u = 22
2 u = 22
1 u = 22 ÷ 2 = 11
Number of packets of 9 = 11
(b)
Number of stickers
= 9 u
= 9 x 11
= 99
Answer(s): (a) 11; (b) 99