The Restaurant's two neon signs are turned on at the same time. Both signs blink as they are turned on. One sign blinks every 9 seconds. The other sign blinks every 15 seconds. In how many seconds will they blink together again ?
In 45 seconds.
9,18,27,36.45
15,30,45
To find out when both signs will blink together again, we need to find the least common multiple (LCM) of 9 and 15.
Step 1: Find the multiples of 9: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, ...
Step 2: Find the multiples of 15: 15, 30, 45, 60, 75, 90, ...
Step 3: Look for the first common multiple in both lists: 45 is the first common multiple.
Therefore, the two signs will blink together again after 45 seconds.
To find out how long it will take for the two signs to blink together again, we need to find the least common multiple (LCM) of the two blinking intervals (9 seconds and 15 seconds).
To find the LCM, we can follow these steps:
1. List the multiples of each blinking interval until we find a common multiple.
For the blinking interval of 9 seconds:
Multiples of 9: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, ...
For the blinking interval of 15 seconds:
Multiples of 15: 15, 30, 45, 60, 75, 90, ...
2. Identify the smallest common multiple from the two lists.
From the multiples listed above, we can see that 45 is the smallest common multiple.
Therefore, the two neon signs will blink together again in 45 seconds.