Using AND and OR (with constraints)| Permutations and Combinations | Grade 11 | Math | Khan Academy

This video tackles problems involving arrangements of digits where we have to take care of constraints. Problems involving even and odd numbers are picked as examples. We first solve for the scenario where repetition is allowed before moving to the scenario where repetition is not allowed. This is where we keep getting stuck until we realise the issue of constraints and the importance of prioritisation. Finally, we figure out the correct approach to solve such problems! Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! (https://www.khanacademy.org/math/ncer...) Timestamps: 00:00 Problem 1 (Even numbers, repetition allowed) 00:49 Finding all 3 digit numbers (ignoring constraint) 01:41 Visualising all possible numbers 01:49 Solution 1 (Finding even numbers) 02:51 Comparing results with actual 03:07 Problem 2 (even numbers, repetition not allowed) 03:30 Attempt 1 (starting from left) 04:25 Comparing results with actual 04:41 Attempt 2 (changing values) 5:29 Comparing results with actual 05:40 Attempt 3 (trying one last time) 06:20 Understanding constraints 07:00 Solving while prioritising constraint Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Ashish Gupta