Question

Write two fractions where the LCD is 20, but the product of the denominators is not 20

Answer 1

Answer: $\frac{1}{4}$ and  $\frac{1}{10}$

Step-by-step explanation:

To calculate the Least Common Denominator (LCD) of two fractions you must descompose each denominators into their prime factors and multiply the commons and non-commons with the largest exponent.

Let's write the following two fractions:

$\frac{1}{4}$ and  $\frac{1}{10}$

The LCD is:

$4=2*2=2^2\\10=2*5$

$LCD=2^2*5\\LCD=4*5\\LCD=20$

So, we have two fractions where LCD is 20.

Let's verify that product of the denominators is not 20:

$4*10=40$ (The product is not 20).