Numbers questions This is a list of recently added questions about numbers. Play numbers quiz and see all the questions. Which currency was the first to be converted to decimal system?Russian ruble. The new ruble introduced with monetary reform of Peter the Great of 1704 was the first currency to be based on decimal system.Created by: smyruvery hard 37% American dolarAmerican dolar863British pound sterlingBritish pound sterling1383frank of revolutionary Francefrank of revolutionary France1441Russian rubleRussian ruble2244coins riddles » What is the sum of all the numbers on the roulette wheel?666. This fact contributed to the naming of the game as Satan one, since 666 it is called the number of the beast by the Book of Revelation.Created by: smyruhard 50% 60060058266666635527837831697100010001185games riddles » Which numeral system was in use in ancient Sumer and Babilon?Sexagesimal. Remnants of highly composite sexagesimal system are in use even today for measuring angles, geographic coordinates and especially time. An hour of time is divided into 60 minutes, which in turn are divided into 60 seconds. Created by: smyruvery hard 31% octaloctal2834binarybinary2468decimaldecimal3071sexagesimalsexagesimal3908mathematics riddles » How many players of one team are there in a pool during the water polo game?7. A team consists of 6 field players and one goalkeeper in the water at any one time. Created by: Paweł Kołodziejczykhard 52% 553394775093998471111392water riddles » Which of the following is true for the solution with the pH=0?The OH − ion concentration is smaller than the H+ ion concentration. In chemistry, pH is a numeric scale used to specify the acidity or alkalinity of an aqueous solution. It is the negative of the logarithm to base 10 of the activity of the hydrogen ion .Traditionally the pH is being defined as: pH = - log10 [H+], where [H+] it is a H+ ions concentration in mol/dm^3 (M). So if pH = 0 this H+ ions concentration is 1 mol/dm^3 and the solution is strongly acidic.Created by: Paweł Kołodziejczykvery hard 25% the OH − ion concentration is smaller than the H+ ion concentrationthe OH − ion concentration is smaller than the H+ ion concentration782the OH − ion concentration is greater than the H+ ion concentrationthe OH − ion concentration is greater than the H+ ion concentration610the OH − ion concentration is equal of the H+ ion concentrationthe OH − ion concentration is equal of the H+ ion concentration847Such solution doesn't existSuch solution doesn't exist810chemistry riddles » What is the volume of a soap bubble with radius R=1 cm?4/3π cm3. Equation for the volume of a sphere: 4/3πR^3.Created by: Paweł Kołodziejczykhard 58% 3/4π cm33/4π cm325684/3π cm34/3π cm378704,3π cm34,3π cm31255It isn't possible to calculateIt isn't possible to calculate1652geometry riddles » What is the result of 2+2*2?6. The multiplication has a priority over addition, and so the result is 2+(2*2) = 2+4 = 6.Created by: Paweł Kołodziejczykvery easy 86% 441538813006610782Not enough dataNot enough data247mathematics riddles » Which of the following numbers is the greatest?1/3. Quite surprisingly, most players answer that both answers 1/3 and 33% are correct. But 1/3 is more than 33%. (it is 33.3333333...)Created by: globalquiz.orghard 53% 1/31/3100450,30,378033%33%1611Both answers 1/3 and 33% are correctBoth answers 1/3 and 33% are correct6379mathematics riddles » Which number is considered unlucky in East Asia?4. Words "four" and "Death" have very similar pronunciation in Chinese, Vietnamese, Korean and Japanese. In East Asia many buildings do not have a 4th floor. Some high-rise residential buildings omit all floor numbers with "4", e.g., 4, 14, 24, 34 and all 40–49 floors. Created by: Sumit Tamanghard 49% 332256445292121224044040649South Korea riddles » Which of the following is a prime number?16769023. A prime number has no positive divisors other than 1 and itself. Hence, a prime bigger than 2 cannot be even. All prime numbers bigger than 5, written in the usual decimal system, end in 1, 3, 7, or 9. Created by: Sumit Tamangaverage 67% 238829902388299015341676902316769023112723837729638377296144911723835117238352544math riddles » Play numbers quiz and see all the questions.