Question

1.) The 10th term of an AP is 68 and its 18th term is 124. The AP is :
এটা সমান্তৰ প্ৰগতিৰ 10-তম পদটো হৈছে 68 আৰু 18-তম পদটোহৈছে124.
| সমান্তৰ প্ৰগতিটো হ'ব ঃ
| (a) 5,14, 23,....... ( b) 5,12, 19,.......(c) 6, 12, 18,.......( d) 4,11, 18,.......​

Answer 1

According to question :-

a+9d=68

a+17d=124

- - -

----------------

-8d=-56

=> d= 7

7therefore,

a=68-9d

=> a=68-9x7

=> a=68-63

=> a=5

therefore A.P

is ;

5, 12,19..........

OPTION (B)

ANS