Reid is 3 years old his sister is 4 times older how old is Reid sister

12yrs

Step-by-step explanation:

Let Reid's age be R and his sister's age be A.

R = 3yrs old

And his sister is 4 times older than Reid.

Therefore, his sister's age will be 4 multiplied by Reid's

That's

A = 4 x 3yrs

= 12yrs

Reid's sister is 12 years old