Question:
The number of ways, in which a student can select one or more questions out of 12 each having an alternative, is
The number of ways, in which a student can select one or more questions out of 12 each having an alternative, is
Options:
- 312 – 1
- 312 + 1
- 312
- 212
- 312 – 1
- 312 + 1
- 312
- 212
Correct Answer: a)
Explanation:
1 Since a student can sol√e each question in 3 different ways – either he can attempt the first
‘ alternati√e or the second alternati√e or he can lea√e it unanswered. ‘
‘ Hence the number of ways in which a student can attempt one or more of the 12 gi√en ‘
1 questions = 312
‘ Now we can consider a case that the student lea√es all the 12 gi√en questions unanswered. ‘
‘ The number of ways, in which a student can select one or more questions out of 12 each
1 ha√ing an alternati√e = 312 -1
H 24. H
(c) 24
hon a
‘
1 Since a student can sol√e each question in 3 different ways – either he can attempt the first
‘ alternati√e or the second alternati√e or he can lea√e it unanswered. ‘
‘ Hence the number of ways in which a student can attempt one or more of the 12 gi√en ‘
1 questions = 312
‘ Now we can consider a case that the student lea√es all the 12 gi√en questions unanswered. ‘
‘ The number of ways, in which a student can select one or more questions out of 12 each
1 ha√ing an alternati√e = 312 -1
H 24. H
(c) 24
hon a
‘