1,7,8,49,50,56,57,343,344,350,351,392,393,399,400 .The above sequence contains sum of distinct power of 7 in increasing order(7^0,7^1,7^1+7^0,7^2 etc.) What is value of term number 38?

• Best Solution :
  Short Cut Method:
  just represent the 38 in binary form...i.e. 100110
  now convert it into base 7 = 7^5+7^2+7
  just add them or check the unit digit(3)
  So the ans z 16863...:)
• 11 years agoHelpfull: Yes(44) No(1)
• Ans=16863
  7^0=1=st term
  7^1=7=2nd term
  7^2=49=4th term
  7^3=343=8th term of the series
  similarly,
  7^5=16807=32th term of the series
  ATQ
  series from 32nd term is
  7^5,7^5+7^0,7^5+7^1,7^5+7^1+7^0,7^5+7^2,.7^5+7^2+7^0,7^5+7^2+7^1
  so the 38th term is
  7^5+7^2+7^1=16807+49+7=16863
• 11 years agoHelpfull: Yes(28) No(0)
• ans:-16863
  38th term= 7^5+56=16863
• 11 years agoHelpfull: Yes(1) No(1)
• similar qus at--http://www.m4maths.com/11402-urgent-maths-question-1-7-8-49-50-56-57-343-344-350-351-392-393-399-400-The-above-sequence-contains-su.html
• 11 years agoHelpfull: Yes(0) No(0)
• 19601..... 7^5+7^4+7^3+7^2+7^0
• 11 years agoHelpfull: Yes(0) No(4)
• the ans is 16864
• 11 years agoHelpfull: Yes(0) No(3)