If someone collapsed and stopped breathing in front of you, would you be able to save their life?
If the answer's no, you're not alone. Research by St John Ambulance (SJA) has found that nearly two-thirds (59%) of people wouldn't feel confident trying to save a life in an emergency.
A quarter (24%) would do nothing at all and just wait for an ambulance, or hope someone else knew first aid.
Perhaps more worrying is that a similar proportion wrongly say they'd know what first aid to do, when in fact the survey shows that many wouldn't do the right thing and could make the situation worse.
It's clear from such figures that many more people need to know first aid, and that's why St John Ambulance has launched a new campaign to encourage the public to learn life-saving techniques.
Clive James, the SJA training development manager, points out that of the estimated 150,000 people who may have lived if they'd had first aid at the scene of their accident/medical emergency, nearly 900 choked to death, 2,500 asphyxiated from a blocked airway and 29,000 died from heart attacks.
He says: "Our mission is to make sure no-one dies through a lack of first aid, so we're running a hard-hitting campaign to raise awareness that people are dying unnecessarily, and that simple techniques can save lives."
While the campaign is urging people to go on SJA first aid courses, it's also offering a free pocket-sized guide featuring first aid skills that can help in five common life-threatening situations: Choking; heart attack; severe bleeding; dealing with an unconscious person; dealing with someone who isn't breathing.
James points out that acquiring first aid knowledge isn't just altruistic, as the majority of accidents happen in the home.
"Statistics show that if you're going to do first aid, invariably it's going to be on somebody you know, because most accidents happen in the home," he says.
Certainly, the SJA survey found that 64% of people felt that a loved one being in an emergency would give them the impetus to learn first aid.
The poll asked people what they'd do in certain medical emergencies, and found that, if faced with a man thrown off his motorbike and not breathing, more than two-fifths (42%) thought they knew what to do - and were wrong.
Of these people, 43% would make the mistake of not moving the man for fear of spinal injury, yet if he wasn't breathing and CPR (cardiopulmonary resuscitation) wasn't given, he'd die.
CPR was exactly what 17-year-old Guy Evans needed when his motorcycle crashed while he was out with friends near his home in Didcot, Oxfordshire, in August 2008.
But he didn't get first aid, and he died.
His mum, Beth Chesney-Evans, says her son didn't die because of massive head injuries or internal bleeding, and she believes he could have lived if he'd been given basic first aid.
"Guy had no injuries at all, but died because his heart apparently stopped and he couldn't breathe, and those are conditions that first aid is designed to deal with until the ambulance arrives," she says.
"I'll never know whether Guy could have survived, but because he didn't get any first aid, he didn't have a chance.
"I'm supporting St John Ambulance's campaign because I want to give others the chance Guy didn't have.
"I don't want him to have died in vain."
James points out that well-intentioned people sometimes carry out first aid after seeing something similar on TV, without realising the TV programme may not have shown the whole procedure.
For example, TV often shows medics being careful not to move people with possible spinal injuries.
But James warns: "If their airway's blocked it doesn't matter what else is wrong with them - if you don't move them they'll die.
"You can't get any worse than dead."
Another situation where mistakes are common is when someone's choking.
Only half of those surveyed would intervene with back blows, which is the correct procedure, while one in 10 would stick their fingers down the choking person's throat, which could push the obstruction further down.
Fortunately, when Alister Fulton's four-year-old daughter Ellie began to choke on a coin, he knew exactly what to do.
The 35-year-old dad had learned first aid with St John Ambulance through his employer, and when Ellie started to choke and her face went red, her eyes bulged and her mouth foamed, he gave her four back blows in the right place to dislodge the coin.
He says: "She was on all fours, coughing.
"I thought she was being sick at first, but as she crawled towards me, it was obvious she was choking.
"I grabbed her and gave her three or four back blows, the last of which dislodged the obstruction.
"It turned out to be a coin that was the perfect size to block a windpipe."
Fulton, who lives in Kent, says that afterwards he thought about what might have happened if he hadn't had first aid training.
"During the emergency I knew exactly what to do and was calm, in spite of knowing that the life at risk was my own daughter's.
"My first aid course had given me the right preparation for the most frightening situation I could imagine.
"Thankfully I'll never know what would have happened if I hadn't had that training. Without it, I might not have been able to laugh and play with my daughter this morning."
Another frequent first aid mistake is made when people are having chest pains.
Many people will put whoever has the pains in the recovery position while they wait for an ambulance.
However, this won't relieve the strain on the heart and could aggravate the condition. Instead, people with chest pain should be sat in a comfortable position.
It's just one of the many vital pieces of advice available in the first aid guide or on SJA courses, which run from three hours to three days and cost from £20.
James stresses: "You can't rely on other people to have the skills - everyone should take the responsibility to learn first aid themselves.
"Make the time to go on a course because it's so important to be prepared when you come across an emergency.
"You never know when you're going to need first aid. Don't leave it till you need it."