Tony's family should start by 9 : 35 am
Solution:
Given that,
Tony's family wants to arrive at the family reunion at 5:00 pm for the supper that is being planned
From given question,
Driving time = 6 hours 30 minutes
Stop for gas one time = 10 minutes
Lunch = 45 minutes
Calculate the total time taken for driving, gas and lunch
⇒ 6 hours 30 minutes + 10 minutes + 45 minutes
⇒ 6 hours 30 minutes + 55 minutes
⇒ 6 hours + 85 minutes
⇒ 6 hours + 60 minutes + 25 minutes
[ since 85 minutes can be written as 60 + 25 minutes ]
We know that,
1 hour = 60 minutes
Therefore,
⇒ 6 hours + 60 minutes + 25 minutes = 6 hours + 1 hour + 25 minutes
⇒ 7 hour 25 minutes
So the total travel time is about 7 hours 25 minutes
If they need to arrive at 5 : 00 pm, then they should start by 9 : 35 am
Because,
Difference between 5 : 00 pm and 9 : 35 am = 7 hours 25 minutes
So Tony's family should start by 9 : 35 am