What formula to add up the values in one column only if a box is checked in the next column?

Hi guys,

I am creating a spreadsheet for my wedding guestlist.

In one column I have a number to tell me the total number of adult guests the party (e.g fried and girlfriend = 2) and then the next two colums are check boxes, one for daytime and the next for nighttime.

What I would like to do is in a footer row under the daytime time checkbox column is to total the first colum (the total number of wedding guests in each party).

I hope that I am explaining this ok, sorry if it is vague.

I understand to use COUNTIF to total the number of checked boxes in the column and have been working on COUNTIF + the sum of the previous column but it's not really working.

Any help will be greatly appreciated.

Thanks,

Phil