¡Hola!
Tenemos los siguientes datos : 7 peruanos 4 chilenos 3 argentinos - - - - - - - - - - - - - - - - - - - - - - 14 personas en total P (probabilidad que la comisión esté formada por 2 peruanos, 2 chilenos y 1 argentino) = ?
Solución : * Se pretende formar comisión eligiendo 5 personas de entre 14, usamos combinaciones simples para comisión probable, veamos : <img src="https://tex.z-dn.net/?f=C_%7B14%2C5%7D%20%3D%20%5Cdfrac%7B14%21%7D%7B5%21%2814-5%29%21%7D%20%3D%20%5Cdfrac%7B14%21%7D%7B5%219%21%7D%20%3D%20%5Cdfrac%7B14%2A13%2A12%2A11%2A10%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%219%21%7D%7B5%2A4%2A3%2A2%2A1%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%219%21%7D" /><img src="https://tex.z-dn.net/?f=C_%7B14%2C5%7D%20%3D%20%5Cdfrac%7B%5Cdiagup%5C%21%5C%21%5C%21%5C%21%5C%2114%5E7%2A13%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%21%5C%2112%5E3%2A11%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%21%5C%2110%5E2%7D%7B%5Cdiagup%5C%21%5C%21%5C%21%5C%215%5E1%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%214%5E1%2A3%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%212%5E1%2A1%7D" /><img src="https://tex.z-dn.net/?f=C_%7B14%2C5%7D%20%3D%20%5Cdfrac%7B7%2A13%2A3%2A11%2A2%7D%7B3%7D%20%3D%20%5Cdfrac%7B6006%7D%7B3%7D%20%3D%20%5Cboxed%7B%5Cboxed%7B2002%7D%7D" /> * * Si la comisión está formada por 2 peruanos, 2 chilenos y 1 argentino : - Elegir 2 peruanos entre 7 del total, quedaremos con la siguiente combinación favorable : <img src="https://tex.z-dn.net/?f=C_%7B7%2C2%7D%20%3D%20%5Cdfrac%7B7%21%7D%7B2%21%287-2%29%21%7D%20%3D%20%5Cdfrac%7B7%21%7D%7B2%215%21%7D%20%3D%20%5Cdfrac%7B7%2A6%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%21%5C%215%21%7D%7B2%2A1%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%21%5C%215%21%7D%20%3D%20%5Cdfrac%7B42%7D%7B2%7D%20%3D%20%5Cboxed%7B21%7D" /> - Elegir 2 chilenos de entre 4 en total, tenemos la siguiente combinación favorable, veamos : <img src="https://tex.z-dn.net/?f=C_%7B4%2C2%7D%20%3D%20%5Cdfrac%7B4%21%7D%7B2%21%284-2%29%21%7D%20%3D%20%5Cdfrac%7B4%21%7D%7B2%212%21%7D%20%3D%20%5Cdfrac%7B4%2A3%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%212%21%7D%7B2%2A1%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%212%21%7D%20%3D%20%5Cdfrac%7B12%7D%7B2%7D%20%3D%20%5Cboxed%7B6%7D" /> - Elegir 1 argentino de entre 3 en total, tenemos la siguiente combinación favorable, veamos : <img src="https://tex.z-dn.net/?f=C_%7B3%2C1%7D%20%3D%20%5Cdfrac%7B3%21%7D%7B1%21%283-1%29%21%7D%20%3D%20%5Cdfrac%7B3%21%7D%7B1%212%21%7D%20%3D%20%5Cdfrac%7B3%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%212%21%7D%7B1%2A%5Cdiagup%5C%21%5C%21%5C%21%5C%212%21%7D%20%3D%20%5Cdfrac%7B3%7D%7B1%7D%20%3D%20%5Cboxed%7B3%7D" />Ahora multiplicamos : <img src="https://tex.z-dn.net/?f=C_%7B7%2C2%7D%2AC_%7B4%2C2%7D%2AC_%7B3%2C1%7D%20%3D%2021%2A6%2A3%20%3D%20%5Cboxed%7B%5Cboxed%7B378%7D%7D" /> * * * Y por fin, encontramos la probabilidad, veamos : <img src="https://tex.z-dn.net/?f=P%20%3D%20%5Cdfrac%7B378%7D%7B2002%7D" />simplifique por 14<img src="https://tex.z-dn.net/?f=P%20%3D%20%5Cdfrac%7B378%7D%7B2002%7D%5Cfrac%7B%5Cdiv14%7D%7B%5Cdiv14%7D" /><img src="https://tex.z-dn.net/?f=%5Cboxed%7B%5Cboxed%7B%5Cboxed%7BP%20%3D%20%5Cfrac%7B27%7D%7B143%7D%7D%7D%7D%5CLongleftarrow%28respuesta%29%5Cend%7Barray%7D%7D%5Cqquad%5Ccheckmark" />Respuesta : b) 27 / 143__________________________¡Espero haberte ayudado, saludos.
DexteR!
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