a boat takes 19 hours for travelling downstream from point a to point b and coming back to a point c which is at midway between a and b. if the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph, what is the distance between a and b?  Choose the correct choice from the following options:
A) 180 km B) 127 km C) 178 km D) 188 km E) 111 km
<gadget id="calculator">14 + 4</gadget>
<output>18</output>

<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">14 - 4</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/18) + (1/20)</gadget>
<output>19/180 = around 0.105556</output>

<gadget id="calculator">19 / (19/180)</gadget>
<output>180</output>

<result>A</result>
a boat takes 19 hours for travelling downstream from point a to point b and coming back to a point c which is at midway between a and b. if the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph, what is the distance between a and b?
divide(19, add(divide(const_1, add(14, 4)), divide(const_1, multiply(subtract(14, 4), const_2))))
"explanation : speed in downstream = ( 14 + 4 ) km / hr = 18 km / hr ; speed in upstream = ( 14 â € “ 4 ) km / hr = 10 km / hr . let the distance between a and b be x km . then , x / 18 + ( x / 2 ) / 10 = 19 â ‡ ” x / 18 + x / 20 = 19 â ‡ ’ x = 180 km . answer : a"