Question

Jack decides to follow a certain diet plan. He drinks 4 quart of water on day one. Each day, he increases his water intake by 1 pint. How many gallon of water will he drink on day 21 of his plan?

• A. $14$ gallon
• B. $3.5$ gallon
• C. $20$ pint
• D. $24$ quart

Answer 1

The correct option is B $3.5$ gallon

Given Jack drinks $4$ quart of water on first day and for subsequent days he drinks $1$ pint more.

So, on day $21$ he will drink $20$ pints and $4$ quarts of water.

We know,
$2$ pints = $1$ quart
$\Rightarrow 1$ pint = $\frac{1}{2}$ quarts
$\Rightarrow 20$ pints = $\frac{20}{2}$ quarts =$10$ quarts
Total water he drank on day $21$ is $10+4=14$ quarts.

Also, we know that $4$ quarts = $1$ gallon
$\Rightarrow 1$ quarts = $\frac{1}{4}$ gallon
$\Rightarrow 14$ quarts = $\frac{14}{4}$ gallons
$\Rightarrow 14$ quarts = $3.5$ gallons.

So, Jack will drink $3.5$ gallons of water on day $21$ of his diet plan.