billy is $\frac 15$ of his brother's age. in $9$ years, billy will be $\frac 12$ of his brother's age. what is the sum of their current ages, in years?

Acircular garden with radius of 8 feet is surrounded by a circular path with a width of 3 feet. what is the approximate area of the path alone? use 3.14 for π

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

Astore has apples on sale for three dollars or 2 pounds how many pounds of apples can you buy for nine dollars if an apple is approximately 5 ounces how many apples can you buy for nine dollars