JEE Main 2020 · MathsNumerical answerNumerical valueHardMulti-step

JEE Main 3 September 2020, Shift 2, Maths Q71

Question 71 of 75 in this shift, Maths question 21 of 25.

Let S be the set of all integer solutions,

(x, y, z)

, of the system of equations

x - 2y + 5z = 0

-2x + 4y + z = 0

-7x + 14y + 9z = 0

such that

15 \leq x^2 + y^2 + z^2 \leq 150

. Then, the number of elements in the set S is equal to __________.

Official answer

8.00

NTA final key (Sep 2020).

Chapter: Determinants
Topic: Cramer's Rule
Idea tested: Variable Ratios in Homogeneous Systems

Same topic in other shifts

All Cramer's Rule questions

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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.