The number of milk teeth in human beings is 20 and the number of permanent teeth is 32. Find the ratio of the number of milk teeth to the number of permanent teeth.
Number of milk teeth = 20
Number of permanent teeth = 32
Ratio of number of milk teeth to the number of permanent teeth is given as
Ratio = 
⇒ Ratio = 
Divide numerator and denominator by 4 we get
⇒ Ratio = 
Therefore, ratio of number of milk teeth to the number of permanent teeth is 5:8
52