Help needed regarding calculating time
 

Hi,

Am having a set of numbers in A,B,C Columns.
Column A is for Distance
Column B is for speed
Column C is for Time

I have query value in D1.
If D1 is less than A1 it should calculate time on the following basis.
D1<A1 Then (D1-A1)/(B1*24)
If D1 is greater than A1 and less than A2 then it should be
C1+(d1-a2)/(b2*24) and so on.
If I drag the formula it is getting collapsed.