Millennials aren't well versed on international currencies, it seems. On Thursday night, popular game show app HQ Trivia posted a straightforward question to the nearly 900,000 participants left playing the game: "What is the official currency of China?" The multiple-choice format offered three potential answers: "renminbi," "yen" and "Chinese dollar," Bloomberg reports. Participants choked. Nearly 720,000 people incorrectly guessed the yen, which is the national currency of Japan. The correct answer is the renminbi, which is often referred to as the yuan. Only 71,000 players got it right. The question was expected to be tough or, as the game puts it, 'savage.' But while HQ expected a third of participants to get the question wrong, it tripped up a full 85 percent of players.

"The Savage Question is the particular moment where almost everyone was wrong and we take a little moment there to learn and appreciate what it reveals about how people think," Rus Yusupov, HQ's chief executive officer, said in a statement to Bloomberg. The question highlights how much millennials, the age group that generally flocks to HQ, still need to learn about money. A 2017 survey by the National Endowment for Financial Education and George Washington University found that only 8 percent of millennials polled showed a high level of financial knowledge, while 24 percent demonstrated just a basic understanding of how to manage their money. The troubling part: 69 percent gave themselves high marks for their financial savvy.

Americans as a whole have a lot to learn as well. When financial services company Financial Engines gave survey respondents an 11-question financial literacy quiz in 2017, only 6 percent passed. Although the same respondents reported feeling as though they're making responsible financial decisions, they weren't doing as stellar a job as they believed they were. "When it comes to your finances, poor decisions you make today can cost you for the rest of your life," says Andy Smith, certified financial planner and senior vice president of financial planning at Financial Engines. Here are the four questions that tripped people up the most. How many can you answer correctly? 1. How much will the typical married couple retiring at age 65 spend on out-of-pocket costs for health care throughout retirement (in today's dollars)? A. $50,000

B. $100,000

C. $157,000

D. $200,000

E. $266,000

F. $330,000 Only 6.9 percent of respondents correctly guessed E. $266,000. Health-care costs are on the rise. According to the survey, the average 65-year-old couple covered by Medicare parts B, D and a supplemental insurance policy will spend more than $250,000 on health-care costs in retirement. Most Americans grossly underestimated. "More than half (58 percent) of those 65 and over — and three-quarters (76 percent) of those ages 55 to 64 — believed the typical married couple retiring today at age 65 will need between $50,000 and $200,000," Financial Engines reports.

2. If you purchase a bond and interest rates rise, what will happen to the price of the bond? A. Rise

B. Stay the same

C. Fall Only 19.9 percent of respondents correctly guessed C. Fall. Bond prices and interest rates have an inverse relationship, so when interest rates rise, bond prices drop and vice versa. 3. A typical 65-year-old man can expect to live, on average, for how many more years? A. About 10 more years

B. About 15 more years

C. About 20 more years

D. About 25 more years

E. About 30 more years Only 28 percent of respondents correctly guessed C. About 20 more years. According to data from the Social Security Administration, men can expect to live to around 84 years old. That should be reflected in their retirement plan so they don't outlive their savings. Women can expect to live longer, to around 87 years old.