Radium-226, a common isotope of radium, has a half-life of 1,620 years. How many grams of a 120-gram sample will remain after t years?

A parallelogram has a base of 3 inches. The height of the parallelogram is 4 inches. What is the area of the parallelogram?

The surface areas of two similar solids are 384 yd2 and 1057 yd2. the volume of the larger solid is 1795 yd3. what is the volume of the smaller solid?

The product lies 6x4/5

Peter can hit a box of 250 golf balls in 10 hours. How many golf balls per hour can Peter hit?

What is 25 and 5/8-12

A shopper buys a 12 - pound bag of oranges for $18.75. What is the unit price?

Harry kept a record of how far he ran each day last week Distance (in miles) Monday 4.5 Tuesday 3.9 Wednesday 4.25 Thursday 3.75 Friday 4.2 On which day did Harry run the greatest number of miles?

Matthew collects purple and red marbles. he has 320 marbles and 65% of them are purple. How many red marbles does he have?

Multiply the complex numbers. (5+1i) (-3+2i)

Joe owns and apple orchard with 20 apple trees. Each year he will plant 7 more. Write and explicit formula for the number of apple trees in the orchard.