Question

Heya ❤❤❤❤
50 points ✌✌

In a question paper, there are two sections . From the total of 10 questions each selection contains 5 questions . A student has to answer 6 questions. If it is not allowed to answer more than 4 question from a section , how many ways a student can select 6 questions ?


Hint : it's combinationn. ​

Answer 1

Here's the Solution :

Given , there are 10 Questions in a paper .

Two sections and each section of the paper contain 5 Questions .

An student has to answer 6 Questions , but it is not allowed to answer more then 4 Questions in a section .

So , total Combination is C(5,4)×C(5,2)+C(5,3)×C(5,3) + C(5,2)×C(5,2)

= 2C(5,4)×C(5,2) + C(5,3)×C(5,3)

= 2 ×[( 5!/4!×1!)×(5!/2!×3!) ]+ [(5!/3!×2!)(5!/3!×2!)]

=[(2× 5 )×(5×4/2) ] +[ (5×4/2)(5×4/2)]

= (2×5×5×2)+(5×2×5×2)

= (10×10) + ( 10×10)

=100+100

=200

Thus in 200 ways a student can select Questions from the paper .

Answer 2

Answer : 200

Explanation :

There are 10 Questions in the paper .

The paper has 2 sections and each has 5 Questions .

A student is not allowed to answer more than 4 Questions in a section .

Therefore , the selection made by the student is

C(5,4)×C(5,2)+ C(5,3)×C(5,3) + C(5,2)×C(5,4)

= 5×5×4/2 + (5×4/2)(5×4/2) + (5×4/2)×5

= 5×10 + 10×10 + 10×5

= 50 + 100 + 50

= 200