A person borrows some money for 8 years at a rate of simple interest. If the ratio of principal and total interest is 5 : 8, then what is the rate ( inpercentage) of interest?
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?