Answer:
Number of en at the lecture = 18
Explanation:
Let the men at lecture be 2x
And women at lecture be 5x.
Remember ratio of men and women is 2 to 5.
Total number of people at the lecture = 63
i.e 2x + 5x = 63
or 7x = 63
or x = 63 /7
or x =9
Hence , Men at the lecture = 2x = 2*9 = 18
And women at the lecture = 5x = 5*9 = 45