InterviewSolution
Saved Bookmarks
| 1. |
The number of terms common between the series 1+ 2 + 4 + 8..... to 100 terms and 1 + 4 + 7 + 10 +... to 100 terms isA. 6B. 4C. 5D. none of these |
|
Answer» Correct Answer - C Soppose `m^(th)` term of first sequence be same as the `n^(th)` term of the second sequences. Then, `2^(m-1)=1+(n-1)xx3rArr2^(m-1)=3n-2rArr2^(m-2)+1=(3n)/(2)` . . . (i) We have, `1lem,nle100` `:." "(3n)/(2)le150` `rArr" "2^(m-2)+1le150` `rArr" "2^(m-2)le149rArrm-2le7rArrnle9rArrm=1,2, . . . ,9`. From (i), we have `n=(2)/(3)(2^(m-2)+1)` We observe that `n inN` for m = 1,3,5,7,9. Hence, there are five common terms in the sequences. |
|