After the presentation to the company CEO, Ms Grant was given q substantial raise her pay went from $18 an hour to $27.90per hour. By what percent did Ms Grant's pay increase?

55%

Step-by-step explanation:

In this question, the scenario is that Ms Grant made a presentation to the company that made her pay rise from $18 an hour to $27.90 an hour. We are now asked to find the percentage increase.

Mathematically, to get this, all we need to do is to subtract the old value from the new value, divided by the new value and multiplied by 100%. What we are saying here is that:

(New value - old value) / old value * 100%

(27.90 - 18) / 18 * 100%

9.9/18 * 100%

That equals 990/18 = 55%

This means Ms Grant's pay increased by 55%