A bus travels 20 km in 30 minutes. What is the average speed of the
bus in km/hr?

Translate the following words into an expression: “the quotient of a number and three is five.”

Me because some of question i don’t understand

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed