Answer: the old price for 1 liter is $0.3
Step-by-step explanation:
Let x represent the old price for 1 liter of petrol.
Last week a man bought 20 liters at the old price. This means that the total amount that the man paid for 20 liters is 20x.
The cost of petrol rises by 2 cents a liter. This means that the new price per liter is x + 2/100 = x + 0.02
This week he bought 10 liters at the new price. This means that the total amount that the man paid for 10 liters is
10(x + 0.02)
= 10x + 0.2
Altogether, the petrol costs $9.20. This means that
20x + 10x + 0.2 = 9.2
30x + 0.2 = 9.2
30x = 9.2 - 0.2
30x = 9
x = 9/30
x = 0.3
Set up a proportion: 3/10= x/80. Then if you multiply 10 by 8, you get 80 on both sides, But, If you do it to the top, you also have to do it to the bottom, so the anser is 3 x 8 , or 24.
Answer:
sandy
Step-by-step explanation:
3/10 = .3
3/7=.43
3/9=.333333
sandy then jeff then kim
2 1/4
2 1/3
These two fractions are both less than 2 1/2 but greater than 2
