# The 21st term of an AP whose first two terms are - 3 and 4, isA. 17B. 137C. 143D. - 143

first two terms of an AP are a = - 3 and a2 = 4.

As we know, nth term of an AP is

an = a + (n - 1)d

where a = first term

an is nth term

d is the common difference

a2 = a + d

4 = - 3 + d

d = 7

Common difference, d = 7

a21 = a + 20d

= - 3 + (20)(7)

= 137

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Champ Quiz | Arithmetic Progression34 mins
Champ Quiz | Arithmetic Progression30 mins
Quiz | Arithmetic Progression44 mins
NCERT | Fundamental Theorem Of Arithmetic45 mins
Lets Check Your Knowledge in A.P.49 mins
Quiz on Arithmetic Progression Quiz32 mins
NCERT | Arithmetic Progression36 mins
Arithmetic progression: Previous Year NTSE Questions34 mins
NCERT | Questions on General Term of an A.P47 mins
Fundamental Theorem of Arithmetic- 143 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses