Question 767643
Similar triangles
a1/a2 = b1/b2 = c1/c2

1.)MN = 6cm, NP = 9cm, RS = 4cm, RT = 6cm, ST = ?
Sol'n: ST = ?
6/4 = MP/4 =9/ST
 1.5= 1.5  =1.5
therefore 9 / 1.5 = 6cm(ST)

2.) Yes. 
 10/8 = 8/6.4 = 10/8
 1.25 = 1.25 = 1.25

3.) 1.8/0.6 = ?/2.4
          3 = 3
   height of the train:
          3*2.4 = 7