If he works 1 hour each day (5 days) = 25$
210/25 = decimals
200/25 = 8
8 hours (40$) per day
8 hours for 5 days = 200$
add 1 hour more to any two days
and thats your answer
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if the question means he has to find 210$ in 1 day, that means
210/5 = 42 hours (not possible)
