A burette pump delivers 60 mL in 15 minutes. What is the rate in mL/h?

A burette pump delivers 60 mL in 15 minutes. What is the rate in mL/h?

• A. 180 mL/h
• B. 120 mL/h
• C. 240 mL/h
• D. 300 mL/h

Answer: (C)

Rate equals volume divided by time. Here, 60 mL is delivered in 15 minutes. Convert 15 minutes to hours: 15 min = 0.25 h. So the rate is 60 mL ÷ 0.25 h = 240 mL/h. If the time were longer, the rate would be smaller; if shorter, the rate would be larger, which helps you see why 240 mL/h is the correct calculation.

Rate equals volume divided by time. Here, 60 mL is delivered in 15 minutes. Convert 15 minutes to hours: 15 min = 0.25 h. So the rate is 60 mL ÷ 0.25 h = 240 mL/h. If the time were longer, the rate would be smaller; if shorter, the rate would be larger, which helps you see why 240 mL/h is the correct calculation.