Sum if a number is contained in a list

Hi,
I need some help with either a sumif or sumproduct formula if possible...

I have uploaded an example file and I need a formula to sum only the entries that are listed on the lookup sheet which match the contract name.

In order to do this the formula will need to look in column G and if there is a match on the lookup sheet then sum column Q. It would also need to match the contract name column U with Column B

I have provided an example of what I need as my description is not very clear.

The formulas would be required in the pink cells.

Hi,

I tried the formula and it worked for the first product but not for the cell in W6. Why would this be?

That formula worked ACE, however I have just been informed of another element Arraaghh

Is there any way I can adapt this:
=SUMIF($B$2:$B$10,U2,$Q$2:$Q$10)

So it looks in column N and does a similar match as the above example where it matches a list (column F) on the sheet lookup.

I also need to adjust the other formula given to add in this additional element
=SUMPRODUCT($Q$2:$Q$10,($B$2:$B$10=U2)*(ISNUMBER(MATCH($G$2:$G$10,Lookup!$C$2:$C$43,0))))

Thanks once again I couldnt get this to work so I will test it and come back to you