PK 2018 Q6
6. Some of the digits in the following correct addition have been replaced by the letters \(P\), \(Q\), \(R\) and \(S\), as shown.
What is the value of \(P + Q + R + S\)?
- A 14
- B 15
- C 16
- D 17
- E 24
| P | 4 | 5 | |
| + | Q | R | S |
| 6 | 5 | 4 |
Pink Kangaroo 2018, Question 6. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: B 15
From the Units digit we see that \(5 + S\) ends in a 4, so \(S = 9\) (and 1 is carried). Then the Tens digit has \(4 + R + 1 = 5\) so \(R = 0\) (and nothing carried). Finally, the Hundreds digit gives \(P + Q = 6\). Then \(P + Q + R + S = 6 + 0 + 9 = 15\).
Solution © UK Mathematics Trust, from the PK 2018 solutions.