Hi-

I attach a Venn diagram in which I've started to put the numbers. You'll see that I've started in the middle: the single female union members, 120 of them. There are 190 female union members altogether, so there must be 70 who aren't single. Where do they go on the diagram?

Continue to work outwards, subtracting as you go, until you've worked out how many go in each region.

Grandad