Case:1n=5!×6!where 5!=arranging of five girlsand 6!=arranging of five boys and five consecutive girls
Case:2__ B __ B __ B __ B __ B __m=5!× 5C4×4!× 6C2×2!where 5!=arranging of five boys,5C4=selecting of four girls,4!=arranging of four girls,6C2=selecting two gaps in between five boys,and 2!=arranging of four consecutive girls and one single girl∴mn=5!× 5C4×4!× 6C2×2!5!×6!=5