GK 2020 Q9
9. Anna wants to walk 5 km on average each day in March. At bedtime on 16th March, she realises that she has walked 95 km so far. What distance does she need to walk on average for the remaining days of the month to achieve her target?
- A 5.4 km
- B 5 km
- C 4 km
- D 3.6 km
- E 3.1 km
Grey Kangaroo 2020, Question 9. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: C 4 km
The total distance Anna wants to walk is (31 × 5) km = 155 km. Since she has walked 95 km up to the 16th of March, she has (155 − 95) km = 60 km to walk in (31 − 16) days = 15 days. Therefore the distance, in km, that she needs to average per day is 60 ÷ 15 = 4.
Solution © UK Mathematics Trust, from the GK 2020 solutions.