Tell how to find 81-36 using mental math

Mary works in a factory that produces 1,000 telephones each day. When 30 telephones were sampled, it was found that 9 were defective. Estimate how many telephones are defective each day.

the ratio of pennies to quarters in a piggy bank is 14:3. if there are 51 quarters in the bank, how many pennies are there

The dimensions of a closed rectangular box are measured as 50 centimeters, 90 centimeters, and 80 centimeters, respectively, with the error in each measurement at most. 2 centimeters.

30000 is blank times as much as 30

If f (x) = 2x-3 and g (x) = x, what is f (g (2))

What is the unit rate for 12 songs in 42 minutes

Adam drove 512 miles in 8 hours. What was the average speed for his trip? Use the formula d=rt. Include all of your calculations in your final answer

What two numbers multipled equals 98

One recipe calls for 3/4 of a cup of Brown sugar. Another recipe calls for 2/3 of a cup which amount is?

Evaluate 2x^2-1 when x=3 A) 5 B) 17 C) 25 D) 35