Find a two-digit number such that three times the tens digit is 2 less than twice the units digit, and twice the number is 20 greater than the number obtained by reversing the digits.
A. 24 B. 42 C. 74 D. 47 E. 72
Correct Answer: D
Explanation
Let the two-digit number be represented as , where is the tens digit and is the units digit.
We are given two conditions:
1. Three times the tens digit is 2 less than twice the units digit.
2. Twice the number is 20 greater than the number obtained by reversing the digits.
Step 1: Simplify Equation (2) Expanding both sides: Now, rearrange the terms:
Step 2: Solve the system of equations From Equation (1): Substitute this into Equation (3): Simplify:
Step 3: Find the value of Substitute into Equation (4):