In an ap the first term …
CBSE, JEE, NEET, CUET
Question Bank, Mock Tests, Exam Papers
NCERT Solutions, Sample Papers, Notes, Videos
Posted by Harshita Kaur 6 years, 6 months ago
- 1 answers
Test
Related Questions
Posted by Parinith Gowda Ms 3 months, 2 weeks ago
- 1 answers
Posted by Hari Anand 6 months, 1 week ago
- 0 answers
Posted by Sahil Sahil 1 year, 4 months ago
- 2 answers
Posted by Parinith Gowda Ms 3 months, 2 weeks ago
- 0 answers
Posted by Vanshika Bhatnagar 1 year, 4 months ago
- 2 answers
Posted by Kanika . 1 month ago
- 1 answers
myCBSEguide
Trusted by 1 Crore+ Students
Test Generator
Create papers online. It's FREE.
CUET Mock Tests
75,000+ questions to practice only on myCBSEguide app
Sia ? 6 years, 6 months ago
Given First term (a) = 8
and, nth term (an) = 33
{tex}\Rightarrow{/tex} a + (n - 1)d = 33
{tex}\Rightarrow{/tex} 8 + (n - 1)d = 33
{tex}\Rightarrow{/tex} (n - 1)d = 33 - 8
{tex}\Rightarrow{/tex} (n - 1)d = 25 .....(i)
and, Sum of first n terms = 123
{tex} \Rightarrow \frac{n}{2}\left[ {a + {a_n}} \right] = 123{/tex}
{tex}\Rightarrow \frac{n}{2}\left[ {8 + 33} \right] = 123{/tex}
{tex} \Rightarrow \frac{n}{2} \times 41 = 123{/tex}
{tex} \Rightarrow n = \frac{{123 \times 2}}{{41}}{/tex}
{tex}\Rightarrow{/tex} n = 6
Put value of n in equation (i)
(6 - 1)d = 25
{tex}\Rightarrow{/tex} 5d = 25
{tex}\Rightarrow d = \frac{{25}}{5} = 5{/tex}
0Thank You