Find x in the following. 1 6! +1 7! = x 8!

Question

Find x in the following.
$\frac{1}{6!}+\frac{1}{7!}=\frac{\text{x}}{8!}$

✓

Answer

$\frac{1}{6!}+\frac{1}{7!}=\frac{\text{x}}{8!}$
$\Rightarrow\text{x}=\frac{8!}{6!}+\frac{8!}{7!}$
$\Rightarrow=\frac{8\times7\times6!}{6!}+\frac{8\times7!}{7!}$
$\Rightarrow\text{x}=8\times7+8$
$\Rightarrow\text{x}=64$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "2 Marks Questions" from Permutations→Permutations — all question types→MATHS STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

Draw the graph of the signum function, $f : R \rightarrow R$, defined by $f ( x )=\left\{\begin{array}{l}\frac{x}{\mid x}, \text { when } x \neq 0 \\ 0, \text { when } x=0\end{array}\right.$
or $f(x)=\left\{\begin{array}{l}1, \text { if } x>0 \\ 0, \text { if } x=0 \\ -1, \text { if } x<0\end{array}\right.$

→

In a survey of 600 students in a school, 150 students were found to be taking tea and 225 taking coffee, 100 were taking both tea and coffee. Find how many students were taking neither tea nor coffee.

→

If the n^th term a_n of sequence is given by $\text{a}_\text{n}=\text{n}^2-\text{n}+1,$ write down its first five terms.

→

Which term in the expansion of $\Bigg\{\Big(\frac{\text{x}}{\sqrt{\text{y}}}\Big)^\frac{1}{3}+\bigg(\frac{\text{y}}{\text{x}^\frac{1}{3}}\bigg)^\frac{1}{2}\Bigg\}^{21}$ contains x and y to one and the same power?

→

Find the equations of the straight lines which pass through (4, 3) and are respectively parallel and perpendicular to the x-axis.

→

A card is drawn at random from a pack of 52 cards, find the probability that the card drawn is:

Not a black card

→

Find the equation of the line passing through (-4, 3) and having slope $\frac{1}{2}.$

→

Find the 7th term in the expansion of $\Big(\frac{4\text{x}}{5}+\frac{5}{2\text{x}}\Big).$

→

In a simultanepous throw of a pair of dice, find the probability of getting,

A total of 9 or 11