Question

A laboratory assistant is in charge of ordering acid for three chemistry classes of 40 students each. Each student requires 120 ml of acid. How many liters of acid should be ordered? The assistant must order by the whole liter.

Answer 1

To answer this question, we have to multiply the volume that each student needs times the number of students:

$40\cdot120mL=4800mL$

Convert this volume to liters (1L=1000mL):

$4800mL\cdot\frac{1L}{1000mL}=4.8L\approx5L$

It means that the assistant must order 5L of acid.