Function machines and simple formulae in words

Here is a number machine.

1. Work out the output when the input is 5.
2. Work out the output when the input is 10.

Here is a number machine.

1. Work out the output when the input is 6.
2. Work out the output when the input is 3.5

Here is a function machine.

input → × 4 → − 3 → output

The input is 2.5. Work out the output.

A bike hire company uses this rule.

Cost in pounds = 6 × number of hours + 10

Sam hires a bike for 4 hours. Work out the cost.

Here is a number machine.

1. Work out the output when the input is 4.
2. Work out the input when the output is 37.

Here is a function machine.

input n → × 3 → + 2 → output

Write an expression for the output.

Here is a number machine.

1. Work out the output when the input is 9.
2. Work out the input when the output is 24.

A bike hire company uses this rule.

Cost in pounds = 6 × number of hours + 10

Fatima pays £58. For how many hours did she hire the bike?

Here is a number machine.

1. Work out the output when the input is 2.5
2. Work out the input when the output is 31.

Here is a number machine with a missing number.

When the input is 4, the output is 14.

1. Work out the missing number in the machine.
2. Use the completed machine to work out the output when the input is 7.

A plumber charges a fixed call-out fee of £40 plus £28 for each hour of work.

The plumber works for h hours on a job.

The total charge for the job is £C.

Write a formula for C in terms of h.

Here is a number machine.

1. Work out the output when the input is 6.
2. Find the input when the output is 30.

Here are two number machines.

1. Work out the output of machine A when the input is 4.
2. Work out the input of machine A when the output is 35.
3. When the input is 4, machine B gives the same output as machine A.
   Work out the value of k.

A tool hire company uses this rule to work out the cost of hiring a floor sander.

Total cost = £45 × number of days + £60 deposit

1. Meera hires the sander for 7 days.
   Work out her total cost.
2. Liam's total cost is £555.
   Work out the number of days Liam hires the sander for.

Here is a number machine.

1. Work out the output when the input is 7.
2. Write down an expression for the output when the input is n.
3. Find the input when the output is 55.

A taxi journey costs a fixed charge of £3 plus £2 for each mile travelled.

A journey of m miles costs £C in total.

1. Write a formula for C in terms of m.
2. A journey costs £25 in total.
   Work out the number of miles travelled.

Here is a number machine.

1. Work out the output when the input is 6.
2. Work out the input when the output is 4.
3. For one value of the input, the output of the machine is equal to the input.
   Work out this value.