JEE Main 2020MathematicsStatisticsMediumMCQ

JEE Main 2020 — Statistics Question with Solution

JEE Main 2020 (05 Sep Shift 2)

Question

If the mean and the standard deviation of the data 3,5,7, a, b are 5and 2 respectively, then a and b are the roots of the equation:

Choose an option

Show full solutionCorrect option: C
Correct answer
Cx2-10x+19=0

Step-by-step explanation

5+3+7+a+b=25⇒a+b=10
S.D. =52+32+72+a2+b25-52=2
=a2+b2+835-25=4⇒a2+b2=62
⇒(a+b)2-2ab=62⇒ab=19
so equation whose roots are a and b is x2-10x+19=0

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About this question

This is a previous-year question from JEE Main 2020, covering the Statistics chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.