We can find equivalent ratios by dividing or multiplying the numerator and denominator by a same number.
20/15
Since 20 and 15 are both divisible by 5, I will divide each by 5.
20/5=4
15/5= 3
4/3 is equivalent to 20/15
Now we can multiply by 2.
20*2
15*2
40/30
40/30 is equivalent to 20/15
Finally, we will multiply 20 and 15 by 3.
20*3=60
15*3= 45
60/45 is equivalent to 20/11
Our three answers : 60/45 and 40/30 and 4/3