Question

The area of a square field is $3200$ $m^2$. How long will a lady take to cross the field diagonally at the rate of $3.3$ km/hr?

• A. $1$ hour $25$ minutes
• B. $1$ hour $15$ minutes
• C. $1$ hour $35$ minutes
• D. $1$ hour $45$ minutes

Answer 1

The correct option is D $1$ hour $45$ minutes

Area of square $=$ $a^2=3200$ sq. m
The length of the diagonal of a square $=$ $d^2=2a^2$
$\Rightarrow d^2=2\times 3200$
$\Rightarrow d^2=6400$
$\Rightarrow d=80$
The time taken to cross a length of $80$ meters while traveling at $3.3$ kmph is given by
time taken $=$ $\frac{80}{3.3}\times \frac{60}{1000}$
$=1$ hour $45$ minutes