PK 2015 Q1
1. What is the units digit of the number \(2015^2 + 2015^0 + 2015^1 + 2015^5\)?
- A 1
- B 5
- C 6
- D 7
- E 9
Pink Kangaroo 2015, Question 1. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: C 6
The units digits of \(2015^2\), \(2015^0\), \(2015^1\), \(2015^5\) are 5, 1, 5, 5, which add to 16. Thus, the units digit of the sum is 6.
Solution © UK Mathematics Trust, from the PK 2015 solutions.