The difference between a two-digit number and the number obtained by interchanging the positions of ...
The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 81. What is the difference between the two digits of that number?
Answer/Solution
9
Steps/Work
Sol.
Let the ten’s digit be x and unit’s digit be y,
Then, (10x + y) - (10y + x) = 81 ⇔ 9 (x - y) = 81
⇔ x - y = 9
Answer E
Let the ten’s digit be x and unit’s digit be y,
Then, (10x + y) - (10y + x) = 81 ⇔ 9 (x - y) = 81
⇔ x - y = 9
Answer E