Use two prime numbers to create a fraction equivalent to 21/49

Suppose that a chemist is mixing two acid solutions, one of 20 % concentration and the other of 30 % concentration. Which of the following concentrations could not be obtained? 1. 22 %, 2. 24 %, 3. 28 %, 4. 34 %

A shipment of 288 reams of paper was delivered. Each of the classrooms received an equal share of the paper. Any extra reams of paper were stored. After the paper was distributed to the classrooms, how many reams of paper were stored

Lake Circulo is a large, circular lake with a walking path around it. The path is 25.12 miles long. What is the approximate area of the lake?

Factor completely. 5x^2+44x-9

A standard showerhead in Andrew's house dispenses 8 gallons of water per minute. Andrew changed this showerhead to an energy-saving one.

What is the optimal way to compute a1a2a3a4a5a6?

This is 10 degrees colder than 4°F.

Estimate. then, divide using the standard algorithm and check 45.15/21

Dwayne has $40 in a savings account that earns 5% annually. The interest is not compounded. How much will he have in 1 year?

A recipe for brownies calls for 4 eggs and 1 1/2 cups of flour. If the recipe makes 15 brownies, how many cups of flour will be needed to make 60 brownies?