Question

in a 42.2 km marathon kuan runs the first 35 km at an average speed of 11 km/h. he walks the next 6 km at 4.5 km/h and stagers the final 1.2 km/h. find kuan average speed for the marathon

Answer 1

Answer:

Kian's average speed for the entire marathon was 7.94 kms/hr

Step-by-step explanation:

35 kms at 11 kms/hr = 35 ÷ 11 = 3 2/11 hrs.

6 kms at 4.5 kms/hr = 6 ÷ 4.5 = 1 1/3 hrs.

1.2 kms at.1.5 kms/hr = 1.2 ÷ 1.5 = 4/5 hrs.

Total # of hours = 3 2/11 + 1 1/3 + 4/5 = 3 30/165 + 1 55/165 + 132/165 = 4 + 217/165 = 4 + 1 52/165 = 5 52/165 hrs.

42.2 kms in 5 52/165 hrs = 42.2 kms in 877/165 hrs = 42.2 kms ÷ (877/165) hrs = 42.2 kms × (165/877) hrs = 7 824⁄877 kms/hr = 7.94 kms/hr.