A bag contains blue marbles and red marbles, 21 in total. The number of blue marbles is 9 less than 2 times the number of red marbles. How many blue marbles are there?

What is the rate unit of running 4 laps in one minute

How does God have magic

How to find the vertex of y=2x^2+12x+16

Shiny White dental insurance costs $258 per year. Approximately one-third of insured people need a filling, which averages $110 each. 80% of insured people get a preventive check-up each year, and the average cost of this visit is $95.

4 times the number of cows plus 2 times the number of ducks

What is the scientific notation for - 20.136

An arithmetic sequence is shown below. You are not given many terms of this sequence, but you do have enough to fill in the missing number. What number goes in the blank? 12, _, 54, ...

You invest $100 and expect your money to grow %8 each year. about how many years will it take for your investment to double?

A person in the audience of a game show has a 14% chance of winning free movie tickets. What is the chance that a person in the audience may not win free movie tickets?

Solve another division problem that has a quotient of 3 and remainder of 12