Option C is the answer.
First lets understand the information mentioned in the question and what needs to be answer in the question. So the questions starts by telling us that "there is 'k' liters of beer which Thor can drink in 'm' minutes and Loki can finish the same amount of beer in 'n' minutes when Loki's drinking speed is less than that of Thor which means that m>n". Then the question asks us "that there if '2k' liter of beer and both Thor and Loki are drinking it at their respective speeds than
how much more beer in liters did Thor drink than Loki".
Now after understanding the information mentioned in the question lets try solving it but as we can see instead of number all the information in question as well as in the options are given in the form of variable. While solving the question with variable is considerable but it gets really messy and hectic sometimes so lets try solving it by assuming some numbers.
So lets assume the following vales for the given variables, we are taking the values which will result in getting the integer numbers because trying to solve for decimal numbers also tend to confuse a lot of people.
K = 30 =>2K = 60
Thor's Drinking Rate = 3
Time take by Thor (m) = 10
Loki's Drinking Rate = 2
Time take by Loki (n) = 15
Combined drinking rate of both Thor and Loki = (3+2) => 5
Drinking time taken when both of them drink together Thor and Loki = 2K/(m+n) => 60/5 => 12
According to this Thor must have drank 36 liter of beer (3*12) and Loki must have drank 24 liter of beer (2*12).
Which according to the question will get in: 36-24 => Thor drank 12 liter more beer than Loki.
Now lets check our options and see which option given us the same answer.
Option A: (k(m-n))/(2(m+n)), Now lets the assumed values of k, m & n into the equation: (30*(10-15))/2(10+15) => -3, We the getting the answer in negative which mean Thor drank less beer than Loki which is incorrect.
EliminatedOption B: (k(m-n)/(m+n), Now lets the assumed values of k, m & n into the equation: (30*(10-15))/(10+15) => -6, We the getting the answer in negative which mean Thor drank less beer than Loki which is incorrect.
EliminatedOption C: (2k(n-m))/(m+n), Now lets the assumed values of k, m & n into the equation: (60*(15-10))/(10+15) => 12, Bingo it exactly the answer which we were looking for.
SelectedOption D: (2k(m-n))/(m+n), Now lets the assumed values of k, m & n into the equation: (60*(10-15))/(10+15) => -12, We the getting the answer in negative which mean Thor drank less beer than Loki which is incorrect.
EliminatedOption E: (2k(m+n))/(n-m), Now lets the assumed values of k, m & n into the equation: (60*(10+15))/(15-10) => 300, This answer is not possible because the total amount of beer is '60' only so it is not possible to drink '300' liter beer from '60' liter.
EliminatedHere we can see only
Option B matches the answer so this must be our answer option.
Bunuel
Thor, drinking at a constant rate, can finish k liters of beer in m minutes, while Loki, drinking at a slower constant rate, can finish the same k liters in n minutes. If they start drinking together and consume 2k liters in total, in terms of m, n, and k, how much more beer in liters did Thor drink than Loki?
A. \(\frac{k(m - n)}{2(m+n)}\)
B. \(\frac{k(m - n)}{m+n}\)
C. \(\frac{2k(n - m)}{m+n}\)
D. \(\frac{2k(m - n)}{m+n}\)
E. \(\frac{2k(m + n)}{n-m}\)