Please can anyone solve the following questions and show working pls.?
1. A man spends 75% of his income, when his income is increased by 20%, he increases his expenditure by 10%. By how much per cent are his savings increased?
2. The marked price of a watch is Rs. 400. After allowing a discount of 25% on the marked price, there was a loss of Rs. 20. Determine the loss per cent.
3. The average of the squares of five consecutive positive integers is 66. Find the average of these five integers.