the average marks in mathematics scored by the pupils of a school at the public examination were 39 . if 4 of these pupils who actually scored 25 , 12 , 15 and 19 marks at the examination had not been sent up , the average marks for the school would have been 44 . find the number of pupils sent up for examination from the school ?
39 x = 25 + 12 + 15 + 19 + ( x – 4 ) 44 39 x = 71 + 44 x - 176 5 x = 105 x = 21 answer : b
divide(subtract(multiply(44, 4), add(add(add(25, 12), 15), 19)), subtract(44, 39))