Question

Very very urgent!!!!!
Please tell !

Answer 1

The second answer given in question is wrong
1190 is right answer.

Answer 2

Given,

$=> Velocity = \frac{2D}{T_1}$

=> V = 2 x 680/4 m/s [ Here, Distance is twice because echo of sound rebounds two times].

=> V = 680/2 m/s

=> V = 340 m

Again,

$=> Velocity = \frac{2D}{T}$

=> 340 = 2D/4+3

=> 340 = 2D/7

=> 2D = 340 x 7

=> 2D = 2380 m

=> D = 2380/2 m

=> D = 1190 m


Hence,


=> Velocity = 340 m/s

Correction :-

=> Distance = 1190 m not 1870 m