Respuesta :
the answer to this is b hope helps i dont really know
The detailed answer is
Let time taken by first person =x
So x = 15
Let time taken by next two persons be y
So 2y=30 or y=15
So x= y = 15
Time taken = 1/x=1/y=1/15
Answer is a
Let time taken by first person =x
So x = 15
Let time taken by next two persons be y
So 2y=30 or y=15
So x= y = 15
Time taken = 1/x=1/y=1/15
Answer is a