21 friends went to a hotel and decided to pay the bill amount equally . but 20 of them could pay rs . 30 each as a result 21 st has to pay rs . 200 extra than his share . find the amount paid by him .
"explanation : average amount paid by 20 persons = rs . 30 increase in average due to rs . 200 paid extra by the 21 st men = rs . 200 / 20 = rs . 10 therefore , average expenditure of 21 friends = rs . 30 + rs . 10 = rs . 40 therefore , amount paid by the 21 st men = rs . 40 + rs . 200 = rs . 240 correct option : e"
add(200, divide(add(multiply(30, 20), 200), 20))