Multiple choice general knowledge math & puzzles

If it were two hours later, it would be half as long until midnight as it would be if it were an hour later. What time is it now?

  1. 8pm

  2. 7.5pm

  3. 6pm

  4. 9pm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let current time be T. If it's two hours later (T+2), time to midnight = M-(T+2). If it's one hour later (T+1), time to midnight = M-(T+1). Given: M-(T+2) = 1/2[M-(T+1)]. Solving: 2(M-T-2) = M-T-1, so 2M-2T-4 = M-T-1, giving M-T = 3. At 9pm, time to midnight is 3 hours. Check: At 11pm (2hrs later), 1 hour to midnight. At 10pm (1hr later), 2 hours to midnight. 1 = 1/2(2) ✓

AI explanation

Let x be the number of hours until midnight right now. Two hours from now, the time until midnight is x−2; one hour from now it is x−1. The condition says x−2 equals half of x−1, so 2(x−2)=x−1, giving x=3. Three hours before midnight is 9pm, so that is the current time.

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