Final answer:
The correct time interval for checking both breathing and a pulse simultaneously is 10 seconds, ensuring a quick response in emergency situations.
Step-by-step explanation:
When checking for breathing and a pulse, the correct time interval to adhere to is approximately 10 seconds. This duration is considered sufficient to determine the absence or presence of a pulse and normal breathing without causing significant delay in starting life-saving procedures if they are needed. It is important not to spend too much time on this step as quick action is crucial in emergency situations.