Question

A bag contains 2 steel balls and 5 brass balls. The total weight is 13 pounds. If 2 steel balls are added and 2 brass balls are removed, the weight decreases to 12 pounds. How much does each kind of ball weigh?

A. steel, 4 pounds; brass, 1 poundB. steel, 1.5 pounds; brass, 2 poundsC. steel, 0.75 pounds; brass, 3 poundsD. steel, 3 pounds; brass, 4 pounds

Answer 1

Long way: set up system of equations and solve
2S+5B=13
4S+3B=12
Solve for S and B.

Answer 2

i already solved for it... i went for c

Answer 3

Sorry, C is not correct.

Answer 4

Try to put 2*0.75+5*3 to see if you get 13?

Answer 5

Do you want to know the short way?

Answer 6

What is the answer to this?

Answer 7

@mathmate plea help?

Answer 8

please* I want to learn the short way, lol

Answer 9

@AccessDenied @Hero Please help me solve this one? :)

Answer 10

its 1.5

Answer 11

@tacosaur
Better late than never!
The short way for this:
A bag contains 2 steel balls and 5 brass balls. The total weight is 13 pounds. If 2 steel balls are added and 2 brass balls are removed, the weight decreases to 12 pounds. How much does each kind of ball weigh?
2S+5B=13
we know that \(adding\) 2S-2B decreases by 1 lb.
so \(subtracting\) 2S-2B will increase by 1 lb.
Then we end up with 0S +7B = 13+1=14 lb, or B=2 lb. Solve for S=(2*2-1)/2=1.5 lb
Ans Steel ball weighs 1.5 lbs, brass ball weighs 2lb