Carcass wrote:
If 2, 4, 6, and 9 are the digits of two 2-digit integers, what is the least possible positive difference between the integers?
A. 28
B. 27
C. 17
D. 13
E. 9
Let's first examine the tens digits.
To minimize the difference between our two numbers, we want the tens digits to be as close as possible.
There are two pairs of numbers that have a difference of 2. They are 2 & 4 and 4 & 6
This gives us two possible cases:
case i: The numbers are 2_ and 4_
case ii: The numbers are 4_ and 6_
case i: The numbers are 2_ and 4_To minimize the difference between these two numbers, we need first unit's digit to be greater than the second units digit
We get: 29 and 46
Difference = 46 - 29 = 17
case ii: The numbers are 4_ and 6_To minimize the difference between these two numbers, we need first unit's digit to be greater than the second units digit
We get: 49 and 62
Difference = 49 - 62 = 13
Answer: D
Cheers,
Brent