A man can row 30 km upstream and 44 km downstream in 10 hours. Also, he can row 40 km upstream and 55 km downstream in 13 hours. Find the rate of current and the speed of the man in still water.
A man purchases a cow for Rs.3000
and sold it on the same day
allowing the buyer a credit of 2
years. If the buyer will pay Rs.3600
after 2 year at a rate of simple
interest 50/7 % per annum, then the man has a gain of