Muft Shiksha
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
Class 11MathematicsPermutations and CombinationsFundamental principle of countingHard
0 reads0 ratings0 helpful

In a (4)-digit telephone extension, the first digit cannot be (0), digits do not repeat, and exactly (2) digits are even. How many extensions are possible?

Answer and explanation

Correct answer: (2160)

If the first digit is even, there are (960) extensions, and if it is odd, there are (1200). Cases are necessary because of the (0) restriction on the first digit.

Related tags

Permutations-And-CombinationsFundamental-PrincipleCountingHardFundamental Principle Of CountingPermutations And CombinationsMathematicsClass 11 Mcq
सुधार सुझाएँ / Earn

Was this question useful?

No ratings yetWrite a review / Rate this question

Student Reviews

No published reviews yet.

KEEP PRACTISING

10 more MCQs
  1. 1A student has 4 shirts and 3 trousers. In how many ways can he choose one shirt and one trouser?
  2. 2In a mobile lock, the first digit can be from (1) to (5) and the second digit can be from (0) to (9). How many such (2)-digit codes are possible?
  3. 3In a school, 7 boys and 5 girls are available for a speech. In how many ways can one speaker be chosen?
  4. 4A library has 8 mathematics books and 6 science books. In how many ways can one book be chosen?
  5. 5A traveler has 3 ways to go from city A to B and 4 ways to go from B to C. How many ways are there to go from A to C?
  6. 6A gift pack has 5 cover options, 2 ribbon options, and 3 card options. In how many ways can one complete pack be made?
  7. 7In a (3)-digit code, each position can have any digit from (0) to (9). If repetition is allowed, how many codes are possible?
  8. 8How many (2)-digit passcodes can be formed from digits (1) to (9) with repetition allowed?
  9. 9How many (2)-digit numbers can be formed from digits (2,4,6,8) without repetition?
  10. 10How many (2)-digit numbers can be formed from digits (0,1,2,3,4) if repetition is allowed?
Found an issue? Help improve this questionMy reports and replies

Add Muft Shiksha to your Home Screen

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