https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:prob-comb/x9e81a4f98389efdf:combinations/v/introduction-to-combinations 2023-07-14T23:21:51.065682509Z Intro to combinations Learn the difference between permutations and combinations, using the example of seating six people in three chairs. Permutations count the different arrangements of people in specific chairs, while combinations count the different groups of people, regardless of order or chair. video https://cdn.kastatic.org/googleusercontent/RBoX6kQqLxz4jz_zTNW-7shI8Smioy10FLn5bnu8c0NaRXhAbfxxF_axu4zVnNFAxPaHaadns3zMnDb29zGS8L0 Intro to combinations Learn the difference between permutations and combinations, using the example of seating six people in three chairs. Permutations count the different arrangements of people in specific chairs, while combinations count the different groups of people, regardless of order or chair. https://cdn.kastatic.org/ka-youtube-converted/iKy-d5_erhI.mp4/iKy-d5_erhI.mp4 378 Combinatoria https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:prob-comb/x9e81a4f98389efdf:combinations/v/combination-formula 2023-07-14T23:21:51.065682509Z Combination formula Learn the difference between permutations and combinations, and how to calculate them using factorials. This video also discusses binomial coefficients and the formula for combinations, nCk. Solidify your understanding with an example: how would one seat six people in four chairs? video https://cdn.kastatic.org/googleusercontent/ftKa0AdfJh2MX9W8r-5G9Prn5vRKWNxxTTHbf9s8YIub47ow3suCb1gqLihE0ELp4DVypHGwQrORrUHe3xwakMOk Combination formula Learn the difference between permutations and combinations, and how to calculate them using factorials. This video also discusses binomial coefficients and the formula for combinations, nCk. Solidify your understanding with an example: how would one seat six people in four chairs? https://cdn.kastatic.org/ka-youtube-converted/p8vIcmr_Pqo.mp4/p8vIcmr_Pqo.mp4 677 Combinatoria https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:prob-comb/x9e81a4f98389efdf:combinations/v/handshaking-combinations 2021-07-01T17:39:51Z Handshaking combinations Sal figures out how different combinations of people can shake hands. video https://cdn.kastatic.org/googleusercontent/XilrYJHItOV5HiVhBUXeIQyUn-8sqpXuhp3MQpb2Kk_nR2IdUYED8v-fiQC5e2i3GCyzWhX2qfnLu1itLm8JYAdX Handshaking combinations Sal figures out how different combinations of people can shake hands. https://cdn.kastatic.org/ka-youtube-converted/boH4l1SgJbM.mp4/boH4l1SgJbM.mp4 449 Combinatoria https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:prob-comb/x9e81a4f98389efdf:combinations/v/permutations-and-combinations-3 2021-07-01T17:39:51Z Combination example: 9 card hands Thinking about how many ways we can construct a hand of 9 cards Sal Khan video https://cdn.kastatic.org/googleusercontent/yYMYE6G_0_3daLq6UAdFR0zLRby40A1SqlBosxHlhv7w14dN4LkFD48skmrIekUg5JOx8tUpfAdWRazggGMH0Pj00w Combination example: 9 card hands Thinking about how many ways we can construct a hand of 9 cards https://cdn.kastatic.org/ka-youtube-converted/SbpoyXTpC84.mp4/SbpoyXTpC84.mp4 462 Combinatoria https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:prob-comb/x9e81a4f98389efdf:combinations/e/combinations_1 2026-03-26T15:40:48.884321068Z Combinations Use combinations to count how many ways you can select k objects from n total objects if order doesn't matter. Mark Wittels exercise