Word problem using compounding addition and division

Question

Robert can swim the first 50 meters of a race in 1 minute. Then he slows down by 12 seconds for each 50 meters of the race. How long does it take him to swim a 400 meter race?

Answer 1

50 meters in 1 minute

50 meters in 1 :12

50 meters in 1:24

50 meters in 1:36

50 meters in 1:48

50 meters in 2 minutes

50 meters in 2:12

50 meters in 2:24

total time 11 minutes 136 seconds

13 minutes 16 seconds