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

The correct option is 1.

Explanation:

According to the combination formula:

`^nC_r=(n!)/(r!(n-r)!)`

The given expression is

`^(10)C_4\cdot ^4C_2`

Using combination formula, the given expression can be written as

`(10!)/(4!(10-4)!)\cdot (4!)/(2!(4-2)!)`

`(10!)/(4!6!)\cdot (4!)/(2!2!)`

`(10* 9* 8* 7* 6!)/(4!6!)\cdot (4!)/(2* 1* 2* 1)`

Cancel out the common factorials.

`(10* 9* 8* 7)/(1)\cdot (1)/(4)`

`(5040)/(4)`

`1260`

Therefore the correct option is 1.