In a class, there are 20 boys and their total score in a test is 810 marks. If the average score of the girls is 37 and that of the whole class is 39, Calculate the; a)Number of students in the class b)Ratio of the total marks of girls to that of boys​

Sherrie is baking a pie for her family. she leaves the room and comes back to 35% of the pie having been eaten before she can put the topping on. how much 1 square inch strips of dough will she need for the top, now that a portion is missing? round your answer to the nearest while nimber.