The position of a digit in a number that determines its value

Working together, Rocco and Giulia can paint a room in 3 hours. It would have taken Rocco 7 hours to do the job alone. Which equation can be used to determine r, Giulia's rate of work in parts per hour? + 3r = 7 + 3r = 1 = r = 3r

Simplify the following equation and solve form 2 (3m) + 3 (5m + 4) = 75

Emily wants to find out if the carpool line around her school causes too much traffic on neighborhood roads.

Radius of a sphere is growing at 5 cm/sec what is the volume when radius is 30cm

Greek city-states began to form in 800 B. C. and in 200 A. D, Christians began getting persecuted. How many years passed between the time that Greek city-states began to form and the persecution of Christians began?

A golf retailer purchases its clubs from a wholesaler at $44 per club. It sells the same clubs to golfers at $75 per club. What is the markup on each club, as a percentage of the wholesale price?

What property is this (8x5) x 10=8x (5x10)

I have two bags of marbles. The first bag contains 6 red marbles, 5 blue marbles, and 4 green marbles. The second bag contains 3 red marbles, 2 blue marble, and 4 green marbles. I will randomly select one marble from each bag.

Terrance is loading two different size boxes onto an elevator, which has a wieght limit. The small boxes weigh 5 kg each and the large boxes weigh 8 kg each.

What is the answer to the question 5x+2x