1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# The number of ways in which the time table for Monday can be made if there must be 5 lessons to be taught that day (Algebra, Geometry, Calculus, Trigonometry, Vector) and topics Algebra and Geometry cannot immediately follow each other are

A
72
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
5!
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
3×5!2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
6!
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is A 72×V×C×T× On these 4 crosses we can arrange two subjects (Algebra and Geometry) in 4P2. And V,C,T can be arranged in 3! ways. Hence, total number of ways =4P2.3!=72 Alternate : The number of required ways = Total ways without restriction − Total ways when Algebra and Geometry are one after the other. Total ways without restriction =5! Total ways when Algebra and Geometry are one after the other =2!×4! (Consider Algebra and Geometry as one object and interchange among themself) The number of required ways =5!−2!×4!=72

Suggest Corrections
0
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program