2010 · Q23
If n is a positive integer, then what is the digit in the unit place of 3^(2n+1) + 2^(2n+1) ?
Elementary MathematicsNumber System
- A0
- B3
- C5
- D7
Explanation
3^(odd) ends 3 or 7, 2^(odd) ends 2 or 8; the sum always ends in 5.
If n is a positive integer, then what is the digit in the unit place of 3^(2n+1) + 2^(2n+1) ?
Explanation
3^(odd) ends 3 or 7, 2^(odd) ends 2 or 8; the sum always ends in 5.