Luke was training for a swimming competition. On Day 1 of his training, he swam 900 m. On Day 2, he swam 0.3 km more than Day 1. For each subsequent training session, he swam a distance of 0.3 km more than the previous training session.
- On Day 6 of his training session, how far did he swim? Give your answer in km.
- On which day did he swim a distance of 3 km?
(a)
1000 m = 1 km
900 m = 0.9 km
Pattern for the distance swam
Day 1: ((1 - 1) x 0.3) + 0.9 = 0.9
Day 2: ((2 - 1) x 0.3) + 0.9 = 1.2
Day 3: ((3 - 1) x 0.3) + 0.9 = 1.5
Formula
Distance swam = ((Number of day - 1) x 0.3) + 0.9
Distance swam on Day 6
= [(6 - 1) x 0.3] + 0.9
= 5 x 0.3 + 0.9
= 1.5 + 0.9
= 2.4 km
(b)
Number of days he swam 3 km
= [(3 - 0.9) ÷ 0.3] + 1
= 2.1 ÷ 0.3 + 1
= 7 + 1
= 8
Answer(s): (a) 2.4 km; (b) 8