Answer:
2.1 hours (2 hours and 6 minutes)
Explanation:
The rate of work of Bobbi is ⅓ while for Deshaun is 1/7 hence combined rate will be
⅓+1/7=(7+3)/21=10/21
The equivalent hours is the reciprocal of the above hence 1021/10=2.1 hours
0.1 of an hour is equivalent to 0.1*60=6 minutes
Therefore, the efforts combined will take 2.1 hours or 2 hours and 6 minutes