AbdurRakib
Each type A machine fills 400 cans per minute,each Type B machine fills 600 cans per minute,and each Type C machine installs 2,400 lids per minute.A lid is installed on each can that is filled and on no can that is not filled.For a particular minute,what is the total number of machines working?
(1) A total of 4,800 cans are filled that minute
(2) For that minute,there are 2 Type B machines working for every Type C machine working
We are given that each Type A machine fills 400 cans per minute, each Type B machine fills 600 cans per minute, and each Type C machine installs 2,400 lids per minute.
We need to determine the total number of machines working for a particular minute. If we let a = the number of Type A machines needed, b = the number of Type B machines needed, and c = the number of Type C machines needed, we need to determine the value of a + b + c.
Statement One Alone:A total of 4,800 cans are filled that minute.
Since a Type C machine installs 2,400 lids per minute, we know that we need 2 Type C machines (i.e., c = 2) to install 4,800 lids after the 4,800 cans are filled in that minute.
Since each Type A machine fills 400 cans per minute and each Type B machine fills 600 cans per minute, we have:
400a + 600b = 4,800
4a + 6b = 48
2a + 3b = 24
However, since we only have one equation but we have two variables, the values of a and b are not unique. For example, a = 12 and b = 0 OR a = 0 and b = 8.
Statement one alone is not sufficient to answer the question.
Statement Two Alone:For that minute, there are 2 Type B machines working for every Type C machine working.
Thus, b/c = 2/1, i.e., b = 2c; however we still cannot determine a + b + c. Statement two alone is not sufficient.
Statements One and Two Together:From statement one, we know that c = 2 and 2a + 3b = 24, and from statement two, we know that b = 2c. Since c = 2 and b = 2c, we see that b = 4.
Next we can substitute 4 for b in the equation 2a + 3b = 24:
2a + 3(4) = 24
2a + 12 = 24
2a = 12
a = 6
Thus a + b + c = 6 + 4 + 2 = 12. We need 12 machines for that particular minute.
Answer: C
Perhaps this was a translation issue on my end by "2 Type B machines working for every Type C machine working" meant 2b=c to me? Are you only allowed to do this when you are given the exact number and not ratios (e.g., c has twice the number of machines as b vs. there are two B machines for every C machine)? So, for translation ratios, you would need to set up the ratio as you did then get to the algebraic equation?
When you mention "From statement one, we know that c = 2", how do you know this? Because 4,800/2400=2?