A class has 30 boys and 20 girls. The average age of boys is 12 yrs and girls 12 yrs. What is the
average age of the whole class."

Jane moves from a house with 71 square feet of closet space to an apartment with 45.44 square feet of closet space. what is the percentage decrease of jane’s closet space?

If rs 900 amounts to rs 1044 in 4 years, what sum will amount to 1368 in 3 1/2 years at the same rate

Darragh has a golden eagle coin in his collection with a mass of 13.551\,\text{g}13.551g. an uncirculated golden eagle coin has a mass of 13.714\,\text{g}13.714g.