Final answer:
In the ratio 1:x, x represents the number of nails you can buy for £1. In the ratio y:£1, y represents the cost of a single nail.
Step-by-step explanation:
a) The first ratio is given as 500 nails to £20. To find the value of x in the ratio 1:x, we need to set up the proportion: 500/£20 = 1/x. Cross-multiplying gives us 500x = £20, and dividing both sides by 500 gives us x = 0.04. So, the value of x is 0.04.
For the second ratio, we are given 500 nails to £20. To find the value of y in the ratio y:£1, we need to set up the proportion: 500/£20 = y/£1. Cross-multiplying gives us 500 = £20y, and dividing both sides by £20 gives us y = 25. So, the value of y is 25.
b) In the ratio 1:x, x represents the number of nails you can buy for £1. In this case, you can buy 0.04 nails for £1. In the ratio y:£1, y represents the cost of a single nail. In this case, a single nail costs £25.
c) Writing the ratios in these ways allows us to compare the number of nails to different monetary amounts. The first ratio allows us to determine how many nails we can buy with a certain amount of money, and the second ratio allows us to determine the cost of a single nail.