If 15Cr15Cr – 1 = 11: 5, find r.

Asked by Sakshi | 1 year ago |  100

Solution :-

Let us use the formula,

nCr = $$\dfrac{ n!}{r!(n – r)!}$$

$$\dfrac{16-r}{r}=\dfrac{11}{5}$$

5(16 – r) = 11r

80 – 5r = 11r

80 = 11r + 5r

16r = 80

r = $$\dfrac{80}{16}$$

= 5

The value of r is 5.

Answered by Sakshi | 1 year ago

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