Emi and Becky are sisters. This formula can be used to calculate Becky’s age, compared to Emi’s age:

e + 4 = b

e stands for Emi’s age.

b stands for Becky’s age.

When Emi is 11, how old will Becky be?

A gardener calculates the perimeter of a garden to work out how much fencing is needed. She uses this formula:

l + w + l + w

l stands for the length of the garden.

w stands for the width of the garden.

Simplify this formula:

A builder needs to calculate the area of a bathroom floor, to work out how much it will cost to tile it. Tiles cost £5 per square metre, plus £10 for delivery. He uses this formula:

5a + 10

a stands for area of the floor (in square metres).

Calculate the cost of tiling a floor, where the area is 10 square metres:

A painter and decorator charges £8 for every hour that she works, and she is currently offering a discount of £5 on each job.

Write the formula she could use to calculate how much money to charge her customers. Use h to represent the number of hours.

The cost of hiring a motorboat is £80 plus £50 per hour.

Write a formula to show the total cost of hiring the motorboat.

T stands for the total cost.

h stands for the number of hours.

A car salesperson earns £1500 a month basic pay plus an extra £500 for each car that he sells.

Write a formula for his monthly pay.

Use P for his monthly pay and n for the number of cars he sells.

Anna says, " If you add 5 to my number and divide by 2, it makes 7."

Which equation below is true?

Ben says, "If you multiply my lucky number by 4 and take away 2, it makes 10."

Which equation below is true?

Sajid says, "If you multiply my lucky number by 5 and then take away 13, you are left with 7.

What is Sajid's lucky number?