Formulae test questions

1

Corinne is an electrician. She charges a flat rate call-out fee of £60 in addition to an hourly rate of £18.

What is the formula for calculating the amount of money Corinne earns on a job depending on how many hours she works for?

2

Wage = Number of hours overtime × £9 + Basic pay

What is a person’s wage when they work for 2 hours overtime and receive £65 basic pay?

3

Bookmakers Ltd. use the same formula to price each printing job.

Cost = Number of books × cost per book + £1,000

What is the cost of printing 200 books when each book costs £6?

4

The cost of hiring a speed boat is found using the formula:

Cost = number of hours × £12 + £24

For how many hours was the boat hired if the total cost is £72?

5

Bookmakers Ltd. use the same formula to price each printing job.

Cost = Number of books × cost per book + £1,000

If the cost to make 400 books was £3,000, what was the cost per book?

6

What is the value of 4r - 3q when r = 7 and q = 5?

7

What is the value of H when I = -2 and J = -7 in the formula H = 4I - 3J?

8

Given that D = 3P + 2K, what is the value of P when D = 24 and K = 3?

9

What is the value of y in the formula \({y}=\frac{{2r}-{4}}{3s}\) when r = 8 and s = 2?

10

What is the value of r in the formula \({y}=\frac{{2r}-{4}}{3s}\) when s = 2 and y = 4?