$\frac{ 7 \times 6 ! \times 5 ! }{ 6 ! \times 3 ! }$
Use $n !=n \times \left( n-1 \right) !$ to expand the expression$\frac{ 7 \times 6 ! \times 5 \times 4 \times 3 ! }{ 6 ! \times 3 ! }$
Cancel out the common factor $6 !$$\frac{ 7 \times 5 \times 4 \times 3 ! }{ 3 ! }$
Cancel out the common factor $3 !$$7 \times 5 \times 4$
Calculate the product$140$