Log inSign up
ISEE Middle Level Quantitative Reasoning · Question of the Day

ISEE Middle Level Quantitative Reasoning Question of the Day

A fresh daily question to build accuracy, reinforce recall, and turn practice into a steady habit.
Thursday, September 17, 2026

Two alarms beep at regular intervals. Alarm A beeps every 6 minutes. Alarm B beeps every 10 minutes. They both beep together at 1:00 PM. What is the first time after 2:00 PM that they will beep together again?

Keep practicing ISEE Middle Level Quantitative Reasoning

Question of the Day

Answer today's ISEE Middle Level Quantitative Reasoning question, reveal the full explanation, then keep the streak going with a new question every day.

Two alarms beep at regular intervals. Alarm A beeps every 6 minutes. Alarm B beeps every 10 minutes. They both beep together at 1:00 PM. What is the first time after 2:00 PM that they will beep together again?

  1. 2:00 PM
  2. 2:10 PM
  3. 2:30 PM (correct answer)
  4. 3:00 PM

Explanation: To find when the alarms beep together, we need to find the least common multiple (LCM) of their intervals, 6 minutes and 10 minutes.

  • Multiples of 6: 6, 12, 18, 24, 30, 36, ...
  • Multiples of 10: 10, 20, 30, 40, ... The LCM of 6 and 10 is 30. So, the alarms beep together every 30 minutes. They start at 1:00 PM. The times they beep together are:
  • 1:00 PM
  • 1:30 PM
  • 2:00 PM
  • 2:30 PM
  • 3:00 PM The question asks for the first time after 2:00 PM. The next time on the list after 2:00 PM is 2:30 PM.