InterviewSolution
Saved Bookmarks
| 1. |
The numbers `1,3,6,10,15,21,28."……"` are called triangular numbers. Let `t_(n)` denotes the bth triangular number such that `t_(n)=t_(n-1)+n,AA n ge 2`. The value of `t_(50)` isA. 1075B. 1175C. 1275D. 1375 |
|
Answer» Correct Answer - C Given sequece `1,3,6,10,15,21,28,"…"` where `t_(n)=t_(n-1)+n,AA n ge 2` So, `t_(n)=[t_(n-2)+(n-1)]+n` `vdots " "vdots " " vdots " "` `t_(n)=t_(1)+2+3+"........"+(n-1)+n` `t_(n)=1+2+3+"......"+n` `t_(n)=(n(n+1))/(2)` `t_(50)=(50xx51)/(2)=25xx51=1275`. |
|