Question

The area of a square field is 24200 sq m. How long will a lady take to cross the field diagonally at the rate of 6.6 km/hr?

• A. $3$ minutes
• B. $2$ minutes
• C. $2.4$ minutes
• D. 22 minutes $40$ seconds

Answer 1

The correct option is B $2$ minutes

Area $=24200m^2$

$\Rightarrow a=\sqrt{24200}=\sqrt{100\times 2\times 121}=110\sqrt{2}m$

Now, $d=\sqrt{2}a=\sqrt{2}\times 110\sqrt{2}=220m$

$\therefore$ $speed=\frac{dis}{time}\Rightarrow time=\frac{dis}{speed}=\frac{220}{\frac{6.6\times 1000}{60}}=\frac{220\times 60}{6600}$

time $=2$min