find the smallest number in a G.P whose sum is 38 and product 1728.
a)12
b)20
c )8
d)none

• c)8
  
  a + ar + ar^2 = 38
  a(ar)(ar^2) = 1728
  So we have two simultaneous equations in a and r. Simplifying them gives
  a (1 + r + r^2) = 38
  a^3 r^3 = 1728 = 12^3
  ar= 12
  
  solving it , we get GP of 8,12,18
  
  and smallest no is 8.... option c
• 13 years agoHelpfull: Yes(3) No(0)
• Answer is 8
  
  x+Y+Z =38
  XYZ=1728
  Y2=xz (If they are in GP)
  
  
• 13 years agoHelpfull: Yes(0) No(1)