Hi, could someone tell me how they got an answer of: x/12 for the question below:
A boat costs x dollars, and this cost is to be shared equally by a group of people. In terms of x, how many dollars less will each person contribute if there are 4 people in the group instead of 3.

Question

Hi, could someone tell me how they got an answer of:   x/12  for the question below:
A boat costs x dollars, and this cost is to be shared equally by a group of people. In terms of x, how many dollars less will each person contribute if there are 4 people in the group instead of 3.

anonymous · Answer

If there are 3 people, each will contribute (x/3) $

If there are 4, each will contribute (x/4) $

The question is how much less the individual contribution will be if there were 4 peopl instead of 3 = (x/3) - (x/4) = (x/12)

anonymous · Answer

but why would it equal to (x/12)?

anonymous · Answer

take LCM
x/3-x/4

LCM  is 12 

$$\Large \frac{x}{3}-\frac{x}{4}=\frac{4x-3x}{12}=\frac{x}{12}$$

anonymous · Answer

oh well that makes a lot more sense c:
thank you

anonymous · Answer

welcome :)

anonymous · Answer

If there are 3 people,each will pay  $ x/3 
If there are 4 people,each will pay  $ x/4
your question says that 'how many dollars less will each person contribute if there are 4 people in the group instead of 3'.This means we should subtract x/4 from x/3
$$\frac{ x }{ 3 }-\frac{ x }{ 4}$$,take lcm,lcm=12
x/3-x/4=4x-3x/12=x/12

anonymous · Answer

tell carl to go away he made my friend spaghetti jr cry