Question

A few numbers of 10's are multiplied and subtracted 1 from the product . The sum of the digits of the resulting number is 72. How many 10's were multiplied ?

Answer 1

8 10's were multiplied

Explanation:

10 - 1 = 9

100 - 1 = 99

1,000 - 1 = 999

10^8 - 1 = 100,000,000 - 1 = 99,999,999

9 × 8 = 72