Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 11,
there are 8 less packets and 4 stickers extra.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 11 |
Number |
1 u |
1 u - 8 |
Value |
9 |
11 |
Total value |
9 u |
11 u - 84 |
(a)
Let the number of packets of 9 be 1 u.
Number of stickers if they are in packets of 9
= 1 u x 9
= 9 u
Number of stickers if they are in packets of 11
= 11(1 u - 8) + 4
= 11 u - 88 + 4
= 11 u - 84
9 u = 11 u - 84
11 u - 9 u = 84
2 u = 84
1 u = 84 ÷ 2 = 42
Number of packets of 9
= 1 u
= 42
(b)
Number of stickers
= 9 u
= 9 x 42
= 378
Answer(s): (a) 42; (b) 378