Of the 300 people in a survey, 180 were men and the rest women. Altogether 190 people answered Yes, and 110 of the men answered Yes. How many of the women answered No?

Complete the two-way table. The women number 300 − 180 = 120. Of the 190 Yes answers, 110 came from men, so 80 came from women, leaving 120 − 80 = 40 women who answered No. Check the other margin: 300 − 190 = 110 people said No, made up of 180 − 110 = 70 men and 40 women. So 80 is the women's Yes count, 70 is the men's No count and 110 is a figure copied straight from the question.