1.

An `AP` consists of `23` terms. If the sum of the three terms of in the middle is `141` and the sum of the last three terms is `261`, then the first term isA. `6`B. `5`C. `4`D. `5`

Answer» Correct Answer - D
`t_(11) + t_(12) + t_(13) = 141`
and `t_(21) + t_(22) + t_(23) = 261`
`:. 3a + 33d = 141 rArr a + 11d = 47`
and `3a + 63d = 261 rArr a + 21d = 87`
On solving eqs. `(i)` and `(ii)`, we get
`a = 3, d = 4`.


Discussion

No Comment Found

Related InterviewSolutions