Question

After a winter storm, the depth of the snow on Burger's Street is $13$ cm. But then, the snow starts melting at a rate of $\frac{1}{4}$ cm per hour. What will be the depth of the snow on Burger's Street after $8$ hours?

• A. $13$ cm
• B. $15$ cm
• C. $11$ cm
• D. $10$ cm

Answer 1

The correct option is C $11$ cm

$\bullet$ Initially, the depth of the snow on Burger's Street $=13$ cm.
$\bullet$ Snow starts melting at the rate of $\frac{1}{4}$ cm per hour.

$\therefore$ After $8$ hours, depth of the snow decreased by
$=(\frac{1}{4}\times 8)$ cm
$=\frac{8}{4}$ cm
$=(8÷4)$ cm
$=2$ cm

This $2$ cm has to be decreased from the initial depth of the snow to get the current depth of the snow on Burger's Street.

$\therefore$ Depth of the snow on Burger's Street after $8$ hours
$=13\text{cm}-2\text{cm}$
$=11$ cm

Hence, the depth of the snow after $8$ hours would be $\underset{–}{11\text{cm}}$ if snow starts melting at a rate of $\frac{1}{4}$ cm per hour from an initial depth of $13$ cm.

$\therefore$ Option (c.) is the correct one.