19.6:X= 1: 10

X= 196

Answer: actual height 196cm.

10 ( 1) 5:8=40:X

X=64

X: three quarters = one fifth: two fifths.

X= three eighths

(3) 1.5:x=3.6:4.8

X=2

(4)x:2=5:2.5

X=4

1 1. Let the height of the model be x.

35:X = 500: 1

X=0.07

answer .......................

Hope to adopt.