Answer:
37min/hour
Explanation:
% of rest with respect to work time= (PWC-Ejob)/(Erest-Ejob)
According to NIOSH 1991, PWC= 3.7kcal/min
E job= 1.5 litre/min of oxygen × 4.9 kcal/litres of oxygen
E job= 7.35 kcal/min
Taking E rest= 1.5 kcal/min
% of rest with respect to work time= (3.7-7.35)/(1.5-7.35)×100
= 62.4%
62.4 % of an hour or 37min/hour.