Answer to Question #33243 in Discrete Mathematics for mehak

Question

In a primary school , the parents were asked about the number of hours they spend per day in helping their chaildren do their homework . there were 90 parents who helped for 1 and a half or half hour.50% did not help , 20% helped more 1 and a half hour and 30% helped for half hour to 1 and half hour .
how many parents were surveyed ?
how many said they did not help ?
how many said they did not helped for more than 1 and a half ?