Question

in an examination the question paper contains three different sections A,B and C containing 4 5 and 6 questions respectively in how many ways a candidate can make a selection of 7 questions selecting at least two questions from it section

Answer 1

your answer is that......

I think....

Answer 2

Answer:

2700

Step-by-step explanation:

According to the question,

Given that,

there are three sections with a number of questions,

A-4, B-5, and C-6

if a candidate can make a selection of 7 questions select at least two questions from its section.

The ways of selection are-

First way $= ^{4}C_{2} X ^{5}C_{2} X ^{6}C_{3}$

Second way $= ^{4}C_{2} X ^{5}C_{3} X ^{6}C_{2}$

third way $= ^{4}C_{3} X ^{5}C_{2} X ^{6}C_{2}$

Total ways for selection questions- $= ^{4}C_{3} X ^{5}C_{2} X ^{6}C_{3} + ^{4}C_{2} X ^{5}C_{3} X ^{6}C_{2} + ^{4}C_{3} X ^{5}C_{2} X ^{6}C_{2}\\\\\\= 6X10X20 + 6X10X15 +4X10X15\\\\\\=1200+900+600\\\\\\=2700$

Hence, 2700 ways a candidate can make a selection of 7 questions by selecting at least two questions from its section.