Basic Life Support (BLS) Certification Exam Version 2– CPR
and Emergency Cardiovascular Care Updated and Latest
Questions and Correct Answers with Rationale
1. What is the recommended depth of chest compressions for an adult victim?
A. At least 2 inches (5 cm)
B. At least 1 inch (2.5 cm)
C. At least 3 inches (7.5 cm)
D. Exactly 1.5 inches (4 cm)
Ans: A
Rationale: High-quality chest compressions are essential for maintaining blood flow to vital organs
during cardiac arrest. In adults, the compressor should push down at least 2 inches but not more than 2.4
inches. Pushing too shallowly will not provide enough circulation to the brain. Pushing too deeply can
increase the risk of internal injuries to the victim. Rescuers should also ensure the chest recoils
completely after each compression. This allow the heart to fill with blood before the next downward
stroke. Consistent depth is a key metric evaluated during BLS performance tests.
,2. What is the correct compression-to-ventilation ratio for a single rescuer performing CPR
on an adult?
A. 30:2
B. 30:1
C. 15:2
D. 15:1
Ans: A
Rationale: For a single rescuer performing adult CPR, the standard ratio is 30 compressions followed by
2 breaths. This ratio is designed to maximize the number of compressions delivered per minute while
providing necessary oxygen. Frequent interruptions for breathing can lower the overall coronary
perfusion pressure. By sticking to 30:2, the rescuer maintains a rhythm that supports both oxygenation
and circulation. This same ratio applies to two-rescuer adult CPR as well. Rescuers should transition
between compressions and breaths as quickly as possible. The goal is to minimize any pauses in chest
compressions to less than 10 seconds.
,3. What is the first step when the Automated External Defibrillator (AED) arrives on the
scene?
A. Attach the pads to the victim’s chest
B. Turn on the AED
C. Press the shock button
D. Clear the victim for analysis
Ans: B
Rationale: The very first thing a rescuer must do when an AED is available is to power it on. Most
modern AEDs provide voice prompts that guide the rescuer through the entire process. Once the device is
on, it will instruct the user to prepare the victim’s chest. This includes removing clothing and ensuring
the skin is dry for proper pad adhesion. Following the voice prompts helps reduce stress and errors
during a high-pressure emergency. It is critical to start the machine early so it can begin its internal self-
checks. Waiting to turn it on can waste precious seconds that are vital for survival. After turning it on, the
rescuer should follow every instruction exactly as given by the device.
4. Which pulse should be checked in an unresponsive infant?
A. Carotid pulse
B. Brachial pulse
C. Radial pulse
D. Femoral pulse
Ans: B
, Rationale: In infants, the brachial artery is the preferred site for checking a pulse during BLS. This artery
is located on the inside of the upper arm between the elbow and shoulder. It is often easier to locate and
palpate than the carotid pulse in a small child. To check it, use two fingers and press gently on the inner
arm. A pulse check should last at least 5 seconds but no more than 10 seconds. If no pulse is felt within
that timeframe, the rescuer must begin CPR immediately. It is important not to waste too much time
searching for a faint pulse. Proper identification of cardiac arrest in infants is crucial for starting life-
saving interventions quickly.
5. What is the recommended rate for chest compressions in all victims?
A. 60 to 80 compressions per minute
B. 100 to 120 compressions per minute
C. 80 to 100 compressions per minute
D. 140 to 160 compressions per minute
Ans: B
Rationale: The compression rate for victims of all ages should be between 100 and 120 compressions
per minute. This specific range is chosen because it optimizes blood flow to the brain and heart.
Compressing slower than 100 times per minute does not generate enough pressure to circulate blood
effectively. Compressing faster than 120 times per minute does not allow the heart enough time to refill
between strokes. Maintaining this steady rhythm is often compared to the beat of certain popular songs.
Rescuers should use a metronome if one is available on their AED or monitor. Consistent speed ensures
that the maximum amount of oxygenated blood reaches vital organs. High-quality CPR depends heavily
on staying within this narrow and effective frequency window.
and Emergency Cardiovascular Care Updated and Latest
Questions and Correct Answers with Rationale
1. What is the recommended depth of chest compressions for an adult victim?
A. At least 2 inches (5 cm)
B. At least 1 inch (2.5 cm)
C. At least 3 inches (7.5 cm)
D. Exactly 1.5 inches (4 cm)
Ans: A
Rationale: High-quality chest compressions are essential for maintaining blood flow to vital organs
during cardiac arrest. In adults, the compressor should push down at least 2 inches but not more than 2.4
inches. Pushing too shallowly will not provide enough circulation to the brain. Pushing too deeply can
increase the risk of internal injuries to the victim. Rescuers should also ensure the chest recoils
completely after each compression. This allow the heart to fill with blood before the next downward
stroke. Consistent depth is a key metric evaluated during BLS performance tests.
,2. What is the correct compression-to-ventilation ratio for a single rescuer performing CPR
on an adult?
A. 30:2
B. 30:1
C. 15:2
D. 15:1
Ans: A
Rationale: For a single rescuer performing adult CPR, the standard ratio is 30 compressions followed by
2 breaths. This ratio is designed to maximize the number of compressions delivered per minute while
providing necessary oxygen. Frequent interruptions for breathing can lower the overall coronary
perfusion pressure. By sticking to 30:2, the rescuer maintains a rhythm that supports both oxygenation
and circulation. This same ratio applies to two-rescuer adult CPR as well. Rescuers should transition
between compressions and breaths as quickly as possible. The goal is to minimize any pauses in chest
compressions to less than 10 seconds.
,3. What is the first step when the Automated External Defibrillator (AED) arrives on the
scene?
A. Attach the pads to the victim’s chest
B. Turn on the AED
C. Press the shock button
D. Clear the victim for analysis
Ans: B
Rationale: The very first thing a rescuer must do when an AED is available is to power it on. Most
modern AEDs provide voice prompts that guide the rescuer through the entire process. Once the device is
on, it will instruct the user to prepare the victim’s chest. This includes removing clothing and ensuring
the skin is dry for proper pad adhesion. Following the voice prompts helps reduce stress and errors
during a high-pressure emergency. It is critical to start the machine early so it can begin its internal self-
checks. Waiting to turn it on can waste precious seconds that are vital for survival. After turning it on, the
rescuer should follow every instruction exactly as given by the device.
4. Which pulse should be checked in an unresponsive infant?
A. Carotid pulse
B. Brachial pulse
C. Radial pulse
D. Femoral pulse
Ans: B
, Rationale: In infants, the brachial artery is the preferred site for checking a pulse during BLS. This artery
is located on the inside of the upper arm between the elbow and shoulder. It is often easier to locate and
palpate than the carotid pulse in a small child. To check it, use two fingers and press gently on the inner
arm. A pulse check should last at least 5 seconds but no more than 10 seconds. If no pulse is felt within
that timeframe, the rescuer must begin CPR immediately. It is important not to waste too much time
searching for a faint pulse. Proper identification of cardiac arrest in infants is crucial for starting life-
saving interventions quickly.
5. What is the recommended rate for chest compressions in all victims?
A. 60 to 80 compressions per minute
B. 100 to 120 compressions per minute
C. 80 to 100 compressions per minute
D. 140 to 160 compressions per minute
Ans: B
Rationale: The compression rate for victims of all ages should be between 100 and 120 compressions
per minute. This specific range is chosen because it optimizes blood flow to the brain and heart.
Compressing slower than 100 times per minute does not generate enough pressure to circulate blood
effectively. Compressing faster than 120 times per minute does not allow the heart enough time to refill
between strokes. Maintaining this steady rhythm is often compared to the beat of certain popular songs.
Rescuers should use a metronome if one is available on their AED or monitor. Consistent speed ensures
that the maximum amount of oxygenated blood reaches vital organs. High-quality CPR depends heavily
on staying within this narrow and effective frequency window.
