If in 2 years at simple interest the principal increases by 18%, what will be the compound interest (in Rs) earned on Rs 7000 in 3 years at the same rate?
P and Q together can make a door in 12 days. They started the work together but after 8 days P left the work. The remaining work is completed by Q alone in 7 more days. In how many days can P alone complete the entire work?