Answer:
∆t = 6.95 minutes
It takes 6.95 minutes longer on Friday than on the other days
Explanation:
Given:
Normal Average speed v1 = 115 km/h
Time taken t1 = 1 h 13 min = (1 + 13/60) hours = 1.2167 h
Distance travelled d = average speed × time taken
d = v1 × t1
Substituting the values;
d = 115 × 1.2167
d = 139.9205 km
On a Friday;
The average speed v2 = 105 km/h
Time taken = distance/average speed
t2 = d/v2
Substituting the values;
t2 = 139.9205/105
t2 = 1.332576190476
t2 = 1.3326 hours
The difference in time taken is;
∆t = t2 - t1
Substituting the values;
∆t = 1.3326 - 1.2167
∆t = 0.1159 hour
Converting to minutes;
∆t = 0.1159 × 60 minutes
∆t = 6.954 minutes
∆t = 6.95 minutes
It takes 6.95 minutes longer on Friday than on the other days
