If a pipe can fill a tank in 2 hours and another pipe can fill the same tank in 40 minutes. How much time in minutes is needed to fill the tank if both the pipes are working together?
A man bought 27 packets of Chilli Milli at $280 each, 9 packets of Chilli Milli at $320 each and 6 packets of Chilli Milli at $360 each. Find the average price per packet of Challi Milli.
A word processing operator typed 44 words per minute. After practice, the operator's speed increased to 55 words per minutes. By what percent did the operator's speed increase?