
### Instruction: help me answer this question Given 5 flags of different colours, how many different signals can be generated if each signal requires the use of 2 flags, one below the other?, think step by step
### Assistant: Since there are 5 flags of different colours, the number of flags possible for the upper flag is 5. Now, as one of the flags is taken, the number of flags remaining for the lower flag in the signal is 4. The number of ways in which signal can be given = 5 × 4 = 20. , The answer is 20
