Number of ways in which three distinct numbers can be selected between 1 and 20 both inclusive, whose sum is even is

Question

Number of ways in which three distinct numbers can be selected between 1 and 20 both inclusive, whose sum is even is (A) 120 (B) 450 (C) 570 (D) none

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/mathematics/e3c868e40293c7f57954f74d0c7dcc00-.png" /> 10 C 3+ 10 C 1 ⋅ 10 C 2=120+450=570.

Q. Number of ways in which three distinct numbers can be selected between 1 and 20 both inclusive, whose sum is even is

120

450

570

none

$^{10} C_{3} +^{10} C_{1} \cdot^{10} C_{2} = 120 + 450 = 570$ .

Q. Number of ways in which three distinct numbers can be selected between 1 and 20 both inclusive, whose sum is even is

120

450

570

none

10C3​+10C1​⋅10C2​=120+450=570.

$^{10} C_{3} +^{10} C_{1} \cdot^{10} C_{2} = 120 + 450 = 570$ .