Answer:
10%
Step-by-step explanation:
Let the third number is X.
then first number = (100-30)% of X
= 70% of X = 7X/10
Second number is (63X/100)
Difference = 7X/10 - 63X/100 = 7X/10
So required percentage is, difference is what percent of first number
=> (7X/100 * 10/7X * 100 )% = 10%