A gentleman buys every year Bank's cash certificates of value exceeding the last year's purchase by Rs. 300. After 20 years, he finds that the total value of the certificates purchased by him is Rs. 83,000. Find the value of the certificates purchased by him in the 13th year.

• Exceedig price is considered as common diff i.e.,d=300 and
  20/2(2a+[20-1]300)=83000
  which gives a=1300
  13th is 1300+12*300=1300+3600=4900
• 10 years agoHelpfull: Yes(2) No(0)
• An=a+(n-1)d
  83000=x+(20-1)300
  x=77300
  A13=a+(n-1)d
  =77300+(13-1)300
  =80900
  
• 10 years agoHelpfull: Yes(0) No(5)