Which of the following ratios is the smallest? 3 : 4, 1 : 2 , 2 : 5,…

3 : 4, 1 : 2 , 2 : 5, 1 : 3

⇒ \(\frac{3}{4}\) = 0.75

⇒ \(\frac{1}{2}\) = 0.50

⇒ \(\frac{1}{3}\) = 0.33

Hence, 1 : 3 is the smallest ratio.