The average weight of 35 apples is 50 grams. If some apples of weight 40 grams each were removed, then average weight becomes 57.5 grams. How many apples of weight 40 grams were removed?
Average weight of 35 apples = 50 grams
=> Total weight of 35 apples = $$50\times35=1750$$ grams
Let $$n$$ apples of 40 grams of weight were removed, then
=> $$\frac{1750-40n}{35-n}=57.5$$
=> $$1750-40n=2012.5-57.5n$$
=> $$57.5n-40n=2012.5-1750$$
=> $$17.5n=262.5$$
=> $$n=\frac{262.5}{17.5}=15$$
=> Ans - (C)
Create a FREE account and get: