IMC 2011 Q1
1. What is the value of 4.5 × 5.5 + 4.5 × 4.5?
- A 36.5
- B 45
- C 50
- D 90
- E 100
Intermediate Mathematical Challenge 2011, Question 1. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: B 45
4.5 × 5.5 + 4.5 × 4.5 = 4.5(5.5 + 4.5) = 4.5 × 10 = 45.
Solution © UK Mathematics Trust, from the IMC 2011 solutions. Longer versions with investigations: Solutions and investigations (PDF).