Robin has a collection of dimes, nickels and quarters. He has 4 times as many dimes as nickels. He has 20 more quarters than nickels. The ratio of the number of dimes to the number of quarters is 3:2. Which equation can be used to calculate the number of nickels, n, Robin has?

Apatient is to be given 35 milligrams of demerol every 4 hours. you have demerol 50 milligrams/milliliter in stock. how many milliliters should be given per dose?

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?

Mr. lash has 42 pounds of dog food to divide among his dogs. if each dog receives 7/8 pounds of food for each feeding, how many times can mr. lash feed his animals?