A boy is to be given dextrose 5% via an infusion pump set at 60 mL/h. How much dextrose will he receive in 1.5 hours?

A boy is to be given dextrose 5% via an infusion pump set at 60 mL/h. How much dextrose will he receive in 1.5 hours?

• A. 60 mL
• B. 75 mL
• C. 90 mL
• D. 120 mL

Answer: (C)

The amount delivered is found by multiplying the infusion rate by the time. At 60 mL per hour for 1.5 hours, the total volume is 60 × 1.5 = 90 mL. You can see it as 60 mL in the first hour plus 60 mL for half of the next hour (30 mL), totaling 90 mL. The 5% concentration doesn’t change the volume—it would change how many grams of dextrose are in that volume. For 90 mL of 5% dextrose, there are 4.5 g of dextrose. So the boy will receive 90 mL.

The amount delivered is found by multiplying the infusion rate by the time. At 60 mL per hour for 1.5 hours, the total volume is 60 × 1.5 = 90 mL. You can see it as 60 mL in the first hour plus 60 mL for half of the next hour (30 mL), totaling 90 mL. The 5% concentration doesn’t change the volume—it would change how many grams of dextrose are in that volume. For 90 mL of 5% dextrose, there are 4.5 g of dextrose. So the boy will receive 90 mL.