Some stickers are packed into exactly packets of 9.
If the stickers are repacked into packets of 14,
there are 8 less packets and 7 stickers extra.
- How many packets are there?
- How many stickers are there?
|
Packets of 9 |
Packets of 14 |
Number |
1 u |
1 u - 8 |
Value |
9 |
14 |
Total value |
9 u |
14 u - 105 |
(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 14
= 14(1 u - 8) + 7
= 14 u - 112 + 7
= 14 u - 105
9 u = 14 u - 105
14 u - 9 u = 105
5 u = 105
1 u = 105 ÷ 5 = 21
Number of packets of 9
= 1 u
= 21
(b)
Number of stickers
= 9 u
= 9 x 21
= 189
Answer(s): (a) 21; (b) 189