Answer:
40%
Step-by-step explanation:
First you have to determine the increase as a number:
increase = new number - original number
That means you have an increase of 210 - 150 = 60
Then you will need to divide the increase by the original number and multiply the answer by 100:
% increase = increase ÷ original number × 100
That will give you: 60 ÷ 150 × 100 = 40