Question

Find the ${10}^{th}$ term from end of the AP $4,9,14,.....,254$.

• A. $198$
  
• B. $209$
• C. $233$
• D. $240$

Answer 1

The correct option is B $209$

To find ${10}^{th}$ term from last let first reverse the A.P.
New A.P is
$254,.....,14,9,4$
$\therefore a=254,d=-5$
Tenth term from last $=a+(n-1)d$
$=254+(10-1)-5$
$=254+9\times -5$
$=254-45=209$