# Given 7 Flags of Different Colours, How Many Different Signals Can Be Generated If a Signal Requires the Use of Two Flags, One Below the Other? - Mathematics

Given 7 flags of different colours, how many different signals can be generated if a signal requires the use of two flags, one below the other?

#### Solution

Number of flags = 7
∴ Number of ways of selecting one flag = 7
Number of ways of selecting the other flag = 6 (as only 6 colours are available for use)
A signal requires use of two flags
∴ Total number of signal that can be generated = 7xx6=42

Concept: Combination
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#### APPEARS IN

RD Sharma Class 11 Mathematics Textbook
Chapter 16 Permutations
Exercise 16.2 | Q 11 | Page 15