The cost of a phone has increased by 10% to £352 work out the original price

The answer is £316.80.

This is because you're working out the original price from a percentage increase.

To do this, you do the original price : (1 - percentage increase as a decimal).

So it would be 352 : (1 - 0.10) which is 352 : 0.9.

And that equals to £316.80.