The sum of three numbers is 164 . If the ratio between the first and second be 2 : 5 and that of between the second and third be 3 : 4 , then find the first number.

24

   I     :      II      :      III      :    Total

   2    :       5

                 3      :        4  

-------------------------------------------------               

  6     :       15    :       20     :     41

41R = 164

1R = 4

 1st Number = 6R = 6 × 4 = 24