Hello Math Help Forum!

Determine how many solutions exist-

Use either elimination or substitution to find the solutions (if any)

1) 4x = 8 and 5y = 15

I was thinking the solution was at (2,3) but I don't know how to use elimination or substitution to show that.

2. An express and local train leave Grays Lake at 3 P.M. and head for Chicago 50miles away. The express travels twice as fast as the local and arrives 1 hour ahead of the local. Find the speed of each train.

I am stumped on this one.

3. On the first day of school, the percentage of boys in a particular class is 60%.During the school year, six girls move away, and are replaced in the class by six boys; this makes the class roster 75% boys. Find the number of boys and girls in the class on the first day of school.

Help on any of these will be greatly appreciated!