Question Recap:
Thor can finish k liters in m minutes → Rate of Thor = k/m liters/min
Loki can finish k liters in n minutes → Rate of Loki = k/n liters/min
They drink together and finish 2k liters in total
We are to find: How much more beer did Thor drink than Loki, in terms of m, n, and k?
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Step 1: Let’s find the time they drink together
Let the total time they drank together be t minutes.
Since both drink at constant rates, total beer drunk = rate × time for each.
So,
Thor drinks = (k/m) × t liters
Loki drinks = (k/n) × t liters
Total consumed = 2k liters
⇒ (k/m)·t + (k/n)·t = 2k
Factor t:
> t·(k/m + k/n) = 2k
t·k(1/m + 1/n) = 2k
t·(1/m + 1/n) = 2
t = 2 / (1/m + 1/n)
Now simplify:
> 1/m + 1/n = (m + n)/(mn)
⇒ t = 2 / ((m + n)/mn) = 2mn / (m + n)
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Step 2: Use t to calculate how much each drank
Thor's consumption:
> Thor drank = (k/m) × t = (k/m) × (2mn)/(m + n) = (2k·n)/(m + n)
Loki's consumption:
> Loki drank = (k/n) × t = (k/n) × (2mn)/(m + n) = (2k·m)/(m + n)
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Step 3: Find the difference
> Thor – Loki = (2k·n)/(m + n) – (2k·m)/(m + n)
= 2k(n – m)/(m + n)
Final Answer: (C)