Mathematics · Probability

JEE Main 2026 — 4 April, Morning Shift — Question 43

A coin is tossed 8 times. If the probability that exactly 4 heads appear in the first six tosses and exactly 3 heads appear in the last five tosses is p, then 96p is equal to ______.

Answer: 9

Numerical answer — enter this value.

Step-by-step solution

x1x2x3x4x5x6x7x8\mathrm{x}_{1} \mathrm{x}_{2} \mathrm{x}_{3} \mathrm{x}_{4} \mathrm{x}_{5} \mathrm{x}_{6} \mathrm{x}_{7} \mathrm{x}_{8} Exactly 4 heads in first six Tosses. (x1x2x3x4x5x6)\left(\mathrm{x}_{1} \mathrm{x}_{2} \mathrm{x}_{3} \mathrm{x}_{4} \mathrm{x}_{5} \mathrm{x}_{6}\right) Exactly 3 heads in last 5 Tosses. i.e. (x4x5x6x7x8)\left(\mathrm{x}_{4} \mathrm{x}_{5} \mathrm{x}_{6} \mathrm{x}_{7} \mathrm{x}_{8}\right) Common tosses (x4x5x6)\left(\mathrm{x}_{4} \mathrm{x}_{5} \mathrm{x}_{6}\right) Let k be number of heads on (x4x5x6)\left(\mathrm{x}_{4} \mathrm{x}_{5} \mathrm{x}_{6}\right) k=1∴\mathrm{k}=1 \therefore ways to overlap =3C1={ }^{3} \mathrm{C}_{1} 3C3×3C1×2C2=3{ }^{3} \mathrm{C}_{3} \times{ }^{3} \mathrm{C}_{1} \times{ }^{2} \mathrm{C}_{2}=3 ways k=2\mathrm{k}=2 3C2×3C2×2C1=18{ }^{3} \mathrm{C}_{2} \times{ }^{3} \mathrm{C}_{2} \times{ }^{2} \mathrm{C}_{1}=18 k=3\mathrm{k}=3 3C1×1=3{ }^{3} \mathrm{C}_{1} \times 1=3 Total ways 24(12)824\left(\frac{1}{2}\right)^{8} 96×2428=6×2416=996 \times \frac{24}{28}=\frac{6 \times 24}{16}=9

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Mathematics
Chapter
Probability
Topic
Introduction to Probability
A coin is tossed 8 times. If the probability that exactly 4 heads… | JEE Main 2026 PYQ with Solution · DhiX AI