Question

npr÷ncr=24 find the value of r

Answer 1

Answer: value of r is 4

Step-by-step explanation:

solution in pic

Hope you get it

Answer 2

The value of r = 4

Given :

$\displaystyle \sf{ {}^{n}P_r \div {}^{n}C_r = 24}$

To find :

The value of r

Solution :

Step 1 of 2 :

Write down the given equation

Here the given equation is

$\displaystyle \sf{ {}^{n}P_r \div {}^{n}C_r = 24}$

Step 2 of 2 :

Find the value of r

$\displaystyle \sf{ {}^{n}P_r \div {}^{n}C_r = 24}$

$\displaystyle \sf{ \implies \bigg( \frac{n!}{(n - r)!} \bigg) \div \bigg( \frac{n!}{r!(n - r)!} \bigg) = 24}$

$\displaystyle \sf{ \implies r! = 24}$

$\displaystyle \sf{ \implies r! = 4 \times 3 \times 2 \times 1}$

$\displaystyle \sf{ \implies r! = 4! }$

$\displaystyle \sf{ \implies r = 4}$

Hence the required value of r = 4