Question

If $\frac{1}{6!}+\frac{1}{7!}=\frac{x}{8!}$, then $x=$ ?

• A. $56$
• B. $64$
• C. $78$
• D. $80$

Answer 1

The correct option is B $64$

Given,

$\frac{1}{6!}+\frac{1}{7!}=\frac{x}{8!}$

or, $\frac{7\times 8}{8!}+\frac{8}{8!}=\frac{x}{8!}$

or, $x=56+8=64$.