finding a value in table

[Memon]

Hello,
How are you wonderful people
I attached an excel sheet in which I will be given two numbers one is from first column (No. 1) and the other is from the table (No.2)

What I want to do is: find No.1 in the first column -> find No2 in the same row of No.1 -> return the value of firs cell in No.2 column

let me rephrase the above sentence
I have to find that number in the table then bring the first value of the column where my original values sits

note: there are duplicate values that's why we can't use Hlookup

https://1drv.ms/x/s!Av1Xu-XOFAQ0gQD4ipWAMoaNxSiR

 

[steve the fish]

See if this works:

=LOOKUP(Q3,ROUND(INDEX($B$3:$N$19,MATCH($Q$4,$A$3:$A$19,0),0),0),$B$2:$N$2)

 

[Memon]

It's working but I need a bit of explanation if it's possible
many many thanks for your effort