Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A purse contains 10 ten rupee coins and 5 five rupee coins. Two coins are randomly drawn. If the expected value of 2 drawn coins is λ, then 9λ4 is equal to
MathematicsProbabilityJEE Main
Solution:
1676 Upvotes Verified Answer
The correct answer is: 37.5
2 coins can be both 10 rupee coins, both 5 rupee coins or one 5 rupee coin and one 10 rupee coin
So, expected value =10C215C2×20+10C215C2×10+10C15C115C2×15
=37×20+221×10+1021×15
=35021=503

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.