Question

solve this with all explaination ​

Answer 1

Answer:(4)

Explanation

Time for 2/5distance =2/5v1

Time for 3/5 distance=3/5v2

Total time taken=(2v2+3v1)/5v1v2

Now total distance=5/5

Average speed=total distance/total time taken

Average speed=5/5/(2v2+3v1)/5v1v2

=(5/5)×5v1v2/2v2+3v1

5v1v2/3v1+2v2 Answer

(4) is the right answe

Answer 2

Answer:answer is option no. 4

Explanation:let total distance be x.

Distance at speed of v1= 2x/5.

And distance at speed of v2=3x/5.

Now time taken to travel 2x/5=2x/5/v1=2x/5v1.........(1)

For distance 3x/5 time=3x/5/v2=3x/5v2........(2)

Total time taken=

Adding (1)&(2):

(2x/5v1)+(3x/5v2)=(2xv2+3xv1)/5v1v2.

So, average speed= total distance travelled / total time taken.

=(x/1)/[(2xv2+3xv1)/(5v1v2)]

=(5v1v2x)/(2xv2+3xv1)

=5v1v2x/x(2v2+3v1)

=5v1v2/2v2+3v1. Ans......