4. While docked, the captain wants to resupply the ship’s missiles and ray-guns. You will need to explain to the captain what information you must know and how that can be used to determine the number of missiles and ray-guns to fill the ship and use all the batteries.
⦁ The ship can hold only 15 weapons total and only has 45 batteries.
⦁ The missiles and ray-guns each require different amounts of batteries to operate.

Question

4. While docked, the captain wants to resupply the ship’s missiles and ray-guns. You will need to explain to the captain what information you must know and how that can be used to determine the number of missiles and ray-guns to fill the ship and use all the batteries. 
⦁	The ship can hold only 15 weapons total and only has 45 batteries. 
⦁	The missiles and ray-guns each require different amounts of batteries to operate.

anonymous · Answer

Can i  please get help? I don't know what's going on with this question

anonymous · Answer

@Hero can you help me?

hero · Answer

Let x = total number of missiles on the ship
     y = total number of ray guns on the ship

Then total number of weapons on the ship is represented by: 
x + y  = 15

Let a = number of batteries per missile
     b = number of batteries per ray gun

Then the total number of batteries is represented by 
ax + by = 45

At this point you would have a system of equations:
  x  + y = 15
ax + by = 45

But it is not solvable unless you know the values of a and b.

anonymous · Answer

I did that but i got a negative number

hero · Answer

The system is $\bf{\text{not solveable}}$ unless you know the values of a and b, which you don't .

anonymous · Answer

So, what do I do now? I don't know the values of a and b because they never told me.

hero · Answer

You should re-read your problem again.

hero · Answer

It explains what it is that you have to do.

anonymous · Answer

What?

anonymous · Answer

oh ok, I think it's saying to explain how to solve it but you can't because you don't a and b

hero · Answer

Correct. More explicitly,

Directions of the problem:

1. Explain to the captain what information needs to be known in order to determine the number of missiles and ray-guns to fill the ship and use all the batteries.

2. Explain how the number of missiles and ray guns can be determined once you know the values of a and b. 

Hint: ( The captain should know such information. )

Suggestion: Assume the captain gives you values of a and b (by making them up yourself)

Then solve the system to demonstrate how the values of x and y can be found.

anonymous · Answer

Oh ok. I get it. Thank you. I can solve the rest now.