Let
x ----> number of men
y ----> number of women
we have that
x/y=4/7 ------> x=(4/7)y -----> equation 1
x+y=209 -----> equation 2
Solve the system of equations
Substitute equation 1 in equation 2
(4/7)y+y=209
solve for y
(11/7)y=209
y=209*7/11
y=133
therefore
