Learn

Saturday, 31 October

JEE Main 2021 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 26 February 2021, Shift 2, Maths Q89

Question 89 of 90 in this shift, Maths question 29 of 30, Section B.

If the arithmetic mean and geometric mean of the pthp^{th} and qthq^{th} terms of the sequence −16,8,−4,2,…-16, 8, -4, 2, \ldots satisfy the equation 4x2−9x+5=04x^2-9x+5=0, then p+qp+q is equal to __________.

Official answer

10

NTA final key.

Idea tested
GP General Term

Same idea in other shifts

Asked 15× in all
  1. 3 Apr 2025, Shift 1 · Q6Let a1,a2,a3,…a_1, a_2, a_3, \ldots be a G.P. of increasing positive numbers. If a3a5=729a_3 a_5 = 729 and a2+a4=1114a_2 + a_4 = \frac{111}{4}, then…EasySingle correct
  2. 7 Apr 2025, Shift 2 · Q7If the sum of the second, fourth and sixth terms of a G.P. of positive terms is 21 and the sum of its eighth, tenth and twelfth terms is…MediumSingle correct
  3. 4 Apr 2024, Shift 1 · Q9Let the first three terms 22, pp and qq, with q≠2q \neq 2, of a G.P. be respectively the 7th7^{th}, 8th8^{th} and 13th13^{th} terms of an…MediumSingle correct
  4. 8 Apr 2024, Shift 2 · Q8In an increasing geometric progression of positive terms, the sum of the second and sixth terms is 703\frac{70}{3} and the product of the…MediumSingle correct
  5. 30 Jan 2024, Shift 2 · Q6Let aa and bb be be two distinct positive real numbers. Let 11th11^{\mathrm{th}} term of a GP, whose first term is aa and third term is…EasySingle correct
  6. 31 Jan 2024, Shift 2 · Q7Let 2nd2^{nd}, 8th8^{th} and 44th44^{th} terms of a non-constant A. P. be respectively the 1st1^{st}, 2nd2^{nd} and 3rd3^{rd} terms of a G. P. If…MediumSingle correct
  7. 13 Apr 2023, Shift 2 · Q8Let a1,a2,a3,…a_1, a_2, a_3, \ldots be a G.P. of increasing positive numbers. Let the sum of its 6th6^{th} and 8th8^{th} terms be 22 and the…MediumSingle correct
  8. 26 Jun 2022, Shift 2 · Q27If a1 (>0),a2,a3,a4,a5a_1\ (> 0), a_2, a_3, a_4, a_5 are in a G.P., a2+a4=2a3+1a_2 + a_4 = 2a_3 + 1 and 3a2+a3=2a43a_2 + a_3 = 2a_4, then a2+a4+2a5a_2 + a_4 + 2a_5 is equal to…MediumNumerical value

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.