how many signals can be made with five flags of different colours , hoisting 1 or 2 or 3 or 4 or all of them , one above the other?
a) 120
b) 325
c) 5
d)none

Question

how many signals can be made with five flags of different colours , hoisting 1 or 2 or 3 or 4 or all of them , one above the other?
a) 120 
b) 325 
c) 5 
d)none

haseeb96 · Answer

@ganeshie8  @phi @inkyvoyd

haseeb96 · Answer

@ikram79

haseeb96 · Answer

@amistre64

haseeb96 · Answer

@satellite73

haseeb96 · Answer

@cwrw238

amistre64 · Answer

what is binary for 11111 ?

amistre64 · Answer

after all, we can have:

00000
00001
00010
00011
00100
00101
00110
00111
01000
etc ...

haseeb96 · Answer

how can i solve it ?

amistre64 · Answer

but i may be misreading the question

amistre64 · Answer

well, i just gave you my interpretation of how to solve it ...

amistre64 · Answer

does the question say that all flags must be used?  its difficult to interpret what its trying to say

haseeb96 · Answer

it say 1 or 2 or 3 or 4 or all of them

amistre64 · Answer

yeah, i can read that much.

can we hoist only 1 flag?  or do we have to hoist all 5 flags such that 1,2,3,4,all [are one above the other]

i got no idea what the last part is spose to suggest

amistre64 · Answer

a permutation of 5 colors would be my next best guess at what this is saying.

haseeb96 · Answer

would u tell me how to solve it ? 
and what is the answer

anonymous · Answer

Suppose you lift all 5 flags. There are $5!$ ways to do this, i.e. $\large{}_{5}P_5$.

With 4 flags, you have $\large{}_{5}P_4$.
With 3, $\large{}_{5}P_3$.
And so on.

With $k$ of $n$ flags, you then have $\large\displaystyle\sum_{k=1}^n\large{}_{n}P_k$. That is, you sum up all the possible numbers of permutations.

anonymous · Answer

@amistre64 your interpretation is correct, though we would ignore the 00000 arrangement, since we have to raise at least 1 flag.

haseeb96 · Answer

D is the correct answer?