JEE Main 2020 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 4 September 2020, Shift 2, Maths Q57

Question 57 of 75 in this shift, Maths question 7 of 25.

Let

a_1, a_2, \ldots, a_n

be a given A.P. whose common difference is an integer and

S_n = a_1 + a_2 + \ldots + a_n

. If

a_1 = 1, a_n = 300

and

15 \leq n \leq 50

, then the ordered pair

(S_{n-4}, a_{n-4})

is equal to :

(1) $(2490, 248)$ Official answer
(2) $(2480, 249)$
(3) $(2490, 249)$
(4) $(2480, 248)$

Official answer

Option 1

NTA final key (Sep 2020).

Chapter: Sequences and Series
Topic: AP and GP
Idea tested: AP General Term

Same idea in other shifts

Asked 7× in all

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27 Jun 2022, Shift 2 · Q6If $a_1, a_2, a_3\,......$ and $b_1, b_2, b_3......$ are A.P., and $a_1=2,\ a_{10}=3,\ a_1b_1=1=a_{10}b_{10}$ , then $a_4\,b_4$ is equal to -MediumSingle correct
3 Aug 2021, Shift 1 · Q86Let $f(x) = x + 1$ and $g$ be maps on $\mathbb{R}$ and $h(n) = (g \circ f)(n+1) - (g \circ f)(n)$ , $n \in \mathbb{N}$ . Further,…HardNumerical value
6 Sep 2020, Shift 2 · Q56The common difference of the A.P. $b_1, b_2, \ldots, b_m$ is 2 more than the common difference of A.P. $a_1, a_2, \ldots, a_n$ . If…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.