What is the percent of increase from 50 to 90

The raw increase from 50 to 90 is 40.
So the question is how much of 50 is 40?

Let's divide the two: 40/50 = .8

So 40 is .8 of 50. But what is .8 in percentage form?

.8 x 100 = 80%

So the move from 50 to 90 is an 80% increase.

SO percent increase have a formula                                                                             |NEW - ORIGINAL| DIVIDED BY ORIGNAL = X/100
       |90-50/50=x/100     
       |40/50|=x/100
       40÷50 = x÷ 100
       Cross multiply
       80% should be an answer
 

31/6= 19/6 19/6 *1/7=19/42