Question

Evaluate the given expression
10c4 • 4c2

1,260
1,278
1,275
1,270

Answer 1

10c^4 * 4 c^2

40 c^2

we need to know the value of c to evaluate

Answer 2

Answer:

The correct option is 1.

Step-by-step explanation:

According to the combination formula:

$^nC_r=\frac{n!}{r!(n-r)!}$

The given expression is

$^{10}C_4\cdot ^4C_2$

Using combination formula, the given expression can be written as

$\frac{10!}{4!(10-4)!}\cdot \frac{4!}{2!(4-2)!}$

$\frac{10!}{4!6!}\cdot \frac{4!}{2!2!}$

$\frac{10\times 9\times 8\times 7\times 6!}{4!6!}\cdot \frac{4!}{2\times 1\times 2\times 1}$

Cancel out the common factorials.

$\frac{10\times 9\times 8\times 7}{1}\cdot \frac{1}{4}$

$\frac{5040}{4}$

$1260$

Therefore the correct option is 1.