Question

$15$ out of $35$ students in the class have pet cats, while the rest own pet dogs. Find the ratio of students who own dogs to the total number of students in the simplest form.

• A. $3:7$
• B. $2:3$
• C. $4:7$
• D. $5:7$

Answer 1

The correct option is C $4:7$

Total number of students $=35$
Number of students who have cats as pets $=15$
Number of students who have dogs as pets $=35-15=20$
The ratio of students who own dogs as pets to the total number of students is $20:35$.
The ratio $20:35$ is not in its simplest form, as it has common factors.
So, we have to convert this ratio into its simplest form by dividing the number by its GCF.

The common factors of $20$ and $35$ are $2$ and $5$.
The GCF of $20$ and $35$ is $5$.
So, to convert the ratio $20:35$ into its simplest form, we have to divide both the numbers by $5$.
The simplest form of the ratio $20:35$ is $4:7$.