The average revenues of 7 consecutive years of a company is Rs 79 lakhs. If the average of first 4 years is Rs 74 lakhs and that of last 4 years is Rs 86 lakhs, what is the revenue for the 4th year?
A certain sum of money becomes double of itself in 15 years at a rate of simple interest. In how many years will it become 5 times of itself at the same rate of simple interest