Owen was training for a swimming competition. On Day 1 of his training, he swam 300 m. On Day 2, he swam 0.7 km more than Day 1. For each subsequent training session, he swam a distance of 0.7 km more than the previous training session.
- On Day 8 of his training session, how far did he swim? Give your answer in km.
- On which day did he swim a distance of 8 km?
(a)
1000 m = 1 km
300 m = 0.3 km
Pattern for the distance swam
Day 1: ((1 - 1) x 0.7) + 0.3 = 0.3
Day 2: ((2 - 1) x 0.7) + 0.3 = 1
Day 3: ((3 - 1) x 0.7) + 0.3 = 1.7
Formula
Distance swam = ((Number of day - 1) x 0.7) + 0.3
Distance swam on Day 8
= [(8 - 1) x 0.7] + 0.3
= 7 x 0.7 + 0.3
= 4.9 + 0.3
= 5.2 km
(b)
Number of days he swam 8 km
= [(8 - 0.3) ÷ 0.7] + 1
= 7.7 ÷ 0.7 + 1
= 11 + 1
= 12
Answer(s): (a) 5.2 km; (b) 12