Question

Which term of $\text{A}\cdot \text{P}\cdot 5,15,\mathrm{25.............}$ will be $130$ more then its ${31}^{st}$ term?

Answer 1

• Ap is 5,15,25.......
  
• a=5 and d=15-5=10
  
• 31st term=a+30d
  
• =5+30*10
  
• =5+300
  
• 31st term =305
  
• an=305+130=435
• a+(n-1)d=435
  
• 5+(n-1)10=435
  
• (n-1)10=435-5
  
• (n-1)=430/10
  
• n-1=43
  
• n=44
  
• It means the 44th term of the given AP will be 130 more than its 31st term.