Question

Find the LCM of 1/7 , 2/5 and 3/15.

• A. 2
• B. 4
• C. 5
• D. 3

Answer 1

Answer:

A. 2

The LCM of 1/7, 2/5, and 3/15 is 2.

1. Simplify the fractions first:

* $\frac{3}{15}$ simplifies to $\frac{1}{5}$

Now the problem is to find the LCM of 1/7,2/5,1/5

2. Use the formula for the LCM of fractions:

* $\text{LCM} = \frac{\text{LCM of Numerators}}{\text{HCF of Denominators}}$

3. Find the LCM of the numerators (1, 2, and 1):

* $\text{LCM}(1, 2, 1) = \mathbf{2}$

4. Find the HCF of the denominators (7, 5, and 5):

* $\text{HCF}(7, 5, 5) = \mathbf{1}$

5. Apply the results to the formula:

* $\text{LCM} = \frac{2}{1} = \mathbf{2}$