Answer:
80
Step-by-step explanation:
Let's say M is the number of men, W is the number of women, and C is the number of children.
M + W + C = 270
M/W = 4/5
W/C = 10/9
We have three equations and three variables, so we can solve this. Let's use substitution.
W = 5/4 M
C = 9/10 W
Substitute into the first equation:
M + 5/4 M + 9/10 W = 270
Substitute again:
M + 5/4 M + 9/10 (5/4 M) = 270
Solve:
M + 5/4 M + 9/8 M = 270
8/8 M + 10/8 M + 9/8 M = 270
27/8 M = 270
M = 80
There are 80 men on the train.
