Question

The doctor prescribes Sally a $210$ ml bottle of medicine with the instructions to take $5$ ml twice a day.
How long does the medicine last?

• A. One week
• B. Four weeks
• C. Three weeks
• D. $3$ days

Answer 1

The correct option is C Three weeks

Twice a day sally will take the medicine $5$ ml
So, $\frac{210}{5}=42$ ml twice a day.
The medicine will take $\frac{42}{2}=21$ days which means $7\text{days}\times 3=21$ days or $3$ weeks.