Update

Muft Shiksha™ एक 100% Free Education Portal है 🇮🇳, जिसका उद्देश्य Class 9–12 के हर विद्यार्थी तक High-Quality Education को पूरी तरह मुफ्त पहुँचाना है। 🇮🇳 हम मानते हैं कि अच्छी शिक्षा किसी student की आर्थिक स्थिति पर निर्भर नहीं होनी चाहिए। 🇮🇳 हर विद्यार्थी को वही Quality Study Material, MCQs, Quizzes, Exam Preparation, Concept-Based Learning और Bilingual Support मिलना चाहिए, जो आमतौर पर महंगी Coaching या Premium Platforms में मिलता है। Muft Shiksha™ 🇮🇳 इसी सोच के साथ बनाया गया है

Subjects
0 reads0 ratings0 helpful

If (^{16}C_{r}=^{16}C_{2r+4}), what is the value of (r)?

Answer and explanation

Correct answer: 4

Use the identity \(^{n}C_r=^{n}C_{n-r}\). Here, \(r\) and \(2r+4\) must be complementary indices, so \(r+(2r+4)=16\). Thus, \(3r=12\), giving \(r=4\). The direct-equality case gives \(r=-4\), which is not a valid index for the combination here. Exam tip: For \(^{n}C_a=^{n}C_b\), check both cases: \(a=b\) and \(a+b=n\).

Related tags

CombinationsNcr SymmetryBinomial CoefficientsIndex EquationsClass 11 MathematicsPermutations And CombinationsMathematicsClass 11 Mcq

Was this question useful?

No ratings yetWrite a review / Rate this question

Student Reviews

No published reviews yet.

Add Muft Shiksha to your Home Screen

In Safari, tap Share, then Add to Home Screen.