A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain?

Choose one answer.

a. 2.5 million years

b. 5 million years

c. 15 million years

d. 10 million years

Describe and correct the error in finding the total cost of a $49 meal with 6%sales tax and an 18%tip. Total cost = 49 + (0.6+0.18) (49). = 49 + (.77) (49) = $87.22

Michael wants to get an 88 average for his tests. he currently has an 86, 86, 86, 90, 89 as his test grades. what grade must michael get on the last test to have at least an 88 average

What is 5y + 12 + 82

Find the domain and the range of f (x) = 2-x+sin x

Julie and Tom each earn money at thier part time job.

Write an expression for the speed of the boat coming back from the island in terms of the other boat's speed. let x be the speed of the boat you are taking to the island.

Write down all the even numbers from 30 to 300 how many times will 6 appear

What type of problems can be solved by using GCF

The data show the last 12 weeks of a familys grocery bill: $60, $60, $60, $80, $120, $120, $150, $120, $300, $200, $100, $90. Which measure of center best represents the data? A. The mode of $60 B. The median of $110 C. The mode of $120 D.

Kyle is renting a jet ski for the day. Below are his two options. Powersports Plus: $30 an hour plus a non-refundable deposit of $50. Sun & Surf: $20 an hour plus a non-refundable deposit of $80. Write an equation that models this situation.