Charlie receives an email from his brother every 4th day and from his sister every 7th day. when will he receive an email from both on the same day?

What is the base of 1/9 to the power of 2

Tomas used 3 1/3 cups of flour and now has 1 2/3cups left. which equation can he use to find f, the number of cups of flour he had to begin with? f+3 1/3=1 2/3 f-3 1/3=1 2/3 3 1/3f=1 2/3 f/3 1/3=1 2/3

Can someone me with my math problem pls my teacher is on my back about this