Foundation November 2017 Paper 1 Q6

(a)

Here is a number machine.

\[\boxed{\text{INPUT}} \longrightarrow \boxed{\text{Multiply by 6}} \longrightarrow \boxed{\text{Subtract 5}} \longrightarrow \boxed{\text{OUTPUT}}\]

(b)

Here is a different number machine.

\[\boxed{\text{INPUT}} \longrightarrow \boxed{\text{Divide by 2}} \longrightarrow \boxed{\text{Multiply by 3}} \longrightarrow \boxed{\text{OUTPUT}}\]

The input is always a positive whole number for this number machine.

Paul says,

‘The output is a whole number.’

Explain clearly why Paul’s statement is sometimes true but not always true.
Use examples to explain your answer. [2]