GK 2017 Q4
4. The sum of three different positive integers is 7. What is the product of these three integers?
- A 12
- B 10
- C 9
- D 8
- E 5
Grey Kangaroo 2017, Question 4. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: D 8
The sum of the three smallest positive integers is 1 + 2 + 3 = 6. Hence the only way to add three different positive integers to obtain a total of 7 is 1 + 2 + 4. Therefore the product of the three integers is 1 × 2 × 4 = 8.
Solution © UK Mathematics Trust, from the GK 2017 solutions.