Some stickers are packed into exactly packets of 10.
If the stickers are repacked into packets of 7,
there are 4 more packets and 2 stickers left.
- How many packets are there?
- How many stickers are there?
|
Packets of 10 |
Packets of 7 |
Number |
1 u |
1 u + 4 |
Value |
10 |
7 |
Total value |
10 u |
7(1 u + 4) + 2 = 7 u + 30 |
(a)
Let the number of packets of 10 be 1 u.
Number of stickers if they are in packets of 10
= 1 u x 10
= 10 u
Number of stickers if they are in packets of 7
= 7 x (1 u + 4) + 2
= 7 u + 28 + 2
= 7 u + 30
10 u = 7 u + 30
10 u - 7 u = 30
3 u = 30
1 u = 30 ÷ 3 = 10
Number of packets of 10
= 1 u
= 10
(b)
Number of stickers
= 10 u
= 10 x 10
= 100
Answer(s): (a) 10; (b) 100