The percent change of 40; 50

25%

Step-by-step explanation:

Change = Final - initial

% Change = (Final - Initial) / Initial * 100%

% Change = (50 - 40) / 40 * 100%

% Change = 10/40 * 100%

% Change = 25%

25%

Step-by-step explanation:

1) Find the difference of the two numbers, do (Largest Number) - (Smallest Number).

2) Use your difference as a fraction. Use the difference over the initial value.

3) Create a proportion

10/40 = x/100

4) Cross multiply, 10*100 = 200, 40*p = 40p

5) Simplify expression 1,000=40p

6) Solve, 1,000/40 = 25

7) Put it as a fraction, 25/100

8) Make it a percent 25%