Can I pls have help with question 8 and 9

Answer:
2.88 kilometers
Step-by-step explanation:
8. If the round trip took 17/20 of an hour.
How long does it take in minutes?
1 hour=60 minutes
17/20*60
=17*3
=51 minutes
9. Calculate the distance between the supermarket and Hilary's house
Speed=distance/time
Distance=speed × time
Total speed=30km/h+12km/h
=42km/h
Total time=17/20 hour
Time spent for 30km/h=30/42*17/20
=510/840
=0.61h
Time spent for 12km/h=12/42*17/20
=204/840
=0.24h
Supermarket to Hilary's house=12km/h
Distance=speed × time
=12×0.24
=2.88 kilometers