Question

Three bells toll at intervals

of 10, 15 and 25 minutes

respectively. They start tolling

together at 7 a.m. At what time 50points please give the correct answer ​

Answer 1

All 3 bells rang at Time 0.

One bell rang at 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135, 144, 153, 162, 171, and 180.

Another bell rang at 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, and 180.

The last bell rang at 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, and 180.

180 (minutes) after the earlier Trifecta was the next Trifecta. 180 is the first number (after zero) evenly divisible by 9, 12, and 15. This will repeat every 180 minutes, providing subsequent Trifectas at 360, 540, 720, 900, etc.