Question

The largest term common to the sequences `1, 11 , 21 , 31 , to100` terms and `31 , 36 , 41 , 46 , to100` terms is `381` b. `471` c. `281` d. none of these
A. 381
B. 471
C. 281
D. 521

Answer 1

Correct Answer - D
`100^(th)` term of 1,11,21,31,.. Is 1+(100-1)10=991.
`100^(th)` term of 31,36,41,46,.. Is 31+(100-1)5=526.
Let the largest common term be 526. Then,
`526=31+(n-1)10`
or n=50.5
But n is an integer, hence n=50. Hence, the largest common term is `31+(50-1)10=521`