Nazima is fly fishing in a stream.

Solution:

Let us take

AB = Tip of fishing rod above the surface of the water

BC = The string rest from directly under the tip of the rod.

AC = The length of string

In ABC right triangle right angled at B

$A C^{2}=A B^{2}+B C^{2}$

$A C^{2}=1.8^{2}+2.4^{2}$

$A C^{2}=3.24+5.76$

 

$A C^{2}=9$

$A C=\sqrt{9}$

$A C=\sqrt{3 \times 3}$

 

$A C=3$

Hence 3 m string is out

The string pulled in 12 seconds is equal to $12 \times 5=60 \mathrm{~cm}=0.6 \mathrm{~m}$ to point $D$

In this case the diagram will look like the following

Now The length of the new string AD = AC − CD = 3.00 − 0.6 = 2.4 m

Now in triangle ADB we have

$1.8^{2}+B D^{2}=2.4^{2}$

$3.24+B D^{2}=5.76$

$B D^{2}=5.76-3.24$

$B D^{2}=2.52$

$B D=1.587$

$\therefore$ Required distance $=1.587+1.2=2.79 \mathrm{~m}$

Hence, the horizontal distance is $2.79 \mathrm{~m}$.