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 ? (25%)
A rectangular lot 50 feet by 100 feet is surrounded on all sides by a concrete walk 5 feet wide. Find the number of square feet in the surface of the walk.
A man bought 27 packets of Chilli Milli at$280 wach, 9 packets of Chilli Milli at$320 each and 6 packets of Chilli Milli at$360 each. Find the average price per packet of Chilli Milli.