Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class
Examples
Example 2
Example 3 Important
Example 4 Important You are here
Example 5
Example 6 (i)
Example 6 (ii)
Example 7
Example 8 Important
Example 9 Important
Example 10
Example 11 Important
Example 12 (i) Important
Example 12 (ii)
Example 13
Example 14 Important
Example 15
Example 16 Important
Example 17
Example 18
Example 19 Important
Example 20 Important
Example 21 Important
Example 22 Important
Example 23 Important
Example 24 Important
Examples
Last updated at May 29, 2023 by Teachoo
Example 4 Find the number of different signals that can be generated by arranging at least 2 flags in order (one below the other) on a vertical staff, if five different flags are available? A signal can have at least 2 flags i.e. flag can have 2 flags or 3 flags or 4 flags or 5 flags We need to calculate separately for each and then add For 2 flags Required number of signals = 5 × 4 = 20 First Flag Second Flag First Flag For 3 flags Required number of signals = 5 × 4 × 3 = 60 For 4 flags Required number of signals = 5 × 4 × 3 × 2 = 120 First Flag Second Flag Fourth Flag For 5 flags Required number of signals = 5 × 4 × 3 × 2 × 1 = 120 ways Thus, Hence, required number of signals = 320