A sequence x1,x2,x3…. Is said to be in harmonic progression if the reciprocals 1/x1,1/x2,1/x3… are
in arithmetic progression. The 5th and 7th term for harmonic progression are 30 and 50 respectively what
is difference between 6th and 4th term ?

• In HP 5th term is 1/30.
  and in HP 7th term is 1/50.
  so
  a+4d=1/30-----(i)
  a+6d=1/50-----(ii)
  solve eq. (i) and (ii)..
  we get
  d= -1/150
  a= 3/50
  4th term is a+3d and 6th term a+5d...
  put the value of a and d..
  now 4th term is =1/25
  6th term is =1/37.5
  so the difference is 37.5-25=12.5
• 12 years agoHelpfull: Yes(30) No(2)
• let HP be like this x1,x2,x3,x4,30,x6,50 nd we knw that difference remain constant.d=2nd trm minus first term. Here x6-30=50-x6.ie on solving x6=40.nw writing the 3 term we see tht diff is of 10 so x4,30,40,50,so we can say tht x4=20.nd diff between x6 nd x4 is 40-20=20 ans
• 12 years agoHelpfull: Yes(1) No(4)