What is the length of the shortest piece of string which can be cut into equal lengths, each 15cm or 20 cm or 25cm long?
15
To find the length of the shortest piece of string that can be cut into equal lengths of 15cm, 20cm, or 25cm, we need to find the least common multiple (LCM) of these three numbers.
Let's start by listing the multiples of each number until we find a common multiple:
Multiples of 15cm: 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, ...
Multiples of 20cm: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, ...
Multiples of 25cm: 25, 50, 75, 100, 125, 150, 175, 200, ...
From the lists above, we can see that the least common multiple (LCM) occurs at 60cm. Therefore, the length of the shortest piece of string that can be cut into equal lengths is 60cm.
To find the length of the shortest piece of string that can be cut into equal lengths of 15cm, 20cm, or 25cm, we need to find the least common multiple (LCM) of these three numbers.
To calculate the LCM, we can follow these steps:
1. Create a list of multiples for each number: 15, 30, 45, 60, 75, ...
2. Look for the first multiple that is common to all three numbers. In this case, we find that 60 is the smallest common multiple of 15, 20, and 25.
Therefore, the length of the shortest piece of string that can be cut into equal lengths of 15cm, 20cm, or 25cm is 60cm.