Answer:
Step-by-step explanation:
Total number of antenna is 15
Defective antenna is 3
The functional antenna is 15-3=12.
Now, if no two defectives are to be consecutive, then the spaces between the functional antennas must each contain at most one defective antenna.
So,
We line up the 13 good ones, and see where the bad one will fits in
__G __ G __ G __ G __ G __G __ G __ G __ G __ G __ G __ G __G __
Each of the places where there's a line is an available spot for one (and no more than one!) bad antenna.
Then,
There are 14 spot available for the defective and there are 3 defective, so the arrange will be combinational arrangement
ⁿCr= n!/(n-r)!r!
The number of arrangement is
14C3=14!/(14-3)!3!
14C3=14×13×12×11!/11!×3×2
14C3=14×13×12/6
14C3=364ways
I hope this helps you
perpendicular lines slopes multiplication -1
M1×M2= -1
1/2×M2= -1
M2= -2
Each number is added by 3 so it's 17 20 23 26 29 32 35 38 41 and so on.
