Let us calculate number of hours worked on a single day
The period between 8,45 and 17,15 , it is actually 8 hours and 30 min
A break of 90 min means 1 hour and 30 min
Then , Shankar works (8 hours 30 min - 1 hour 30 min) equals to 7 hours / day
In five days he works 7 x 5 = 35 hours