15 29 47 73 115 ?

• 15*2 – 1 = 29
  29*2 – 11 = 47
  47*2– 21 = 73
  73*2 -31=115
  115*2-41=189
• 7 years agoHelpfull: Yes(1) No(0)
• 15 29 47 73 115 189
• 8 years agoHelpfull: Yes(0) No(0)
• the difference between difference of consecutive terms are in GP with first term 4 and r = 4. i.e, 29-15=14, 47-29=18, 73-47 = 26, 115-73 = 42. Now differences, 18-14 = 4, 26 - 18 = 8, 42 - 26 = 16, which is a GP. So next term in GP = 32. So 42+32 = 74. Next term in series = 115+74 = 189
• 7 years agoHelpfull: Yes(0) No(0)