Question

If 3:x::12:20 are in proportion time value of x

Answer 1

3/x:: 12/20
12x=60
x=5

Answer 2

Hey friend your answer is here

3/x =12/60

after cross multiplication,

20×3 = 12×x

so 60= 12x

60/12= x

so x = 5

I hope this answer will help you.