Multiply a number by 10 to get 72 more than the original number. What's the original number?

Multiply a number by 10 to get 72 more than the original number. What's the original number?

72 (10-1) = 72 (9), = 8. A: the original number is 8

Multiply a number by 10 to get 72 more than the original number. What's the original number?

72 (10-1) = 72 (9), = 8. A: the original number is 8

The number 30% more than a number is 39. What's half of the number

Let this number be X
（1+30%）x=39
1.3x=39
x=30
Half of the number: 30 / 2 = 15

20% of a number is 8 less than 30% of the number. What is the number? (equation solution)

30% x-20% x = 8, the solution is x = 80