a student orders a pizza
1 day she eats half and 2 day she eats 1/3 of the rest
3 day she eats 1/4 of what is left
4 days she eats 1/5 of what is left
5 day she does not eat anymore because the pizza is not good anymore. how much of the whole pizza does she throw away?
+191 set whole pizza as x
day 1 she eats 1/2x
day 2 she eats 1/3(1/2x), which is 1/6x
day 3 she eats 1/4(1/3x), which is 1/12x
day 4 she eats 1/5(1/4x) which is 1/20x
Total eaten over 4 days: (1/2+1/6+1/12+1/20)x = 4/5x
Answer = left over = 1/5 of the whole pizza
