csat-suneung 2020 Q22

csat-suneung · South-Korea · csat__math-humanities 3 marks Permutations & Arrangements Factorial and Combinatorial Expression Simplification

Find the value of ${ } _ { 7 } \mathrm { P } _ { 2 } + { } _ { 7 } \mathrm { C } _ { 2 }$. [3 points]

Find the value of ${ } _ { 7 } \mathrm { P } _ { 2 } + { } _ { 7 } \mathrm { C } _ { 2 }$. [3 points]