Numbers questions This is a list of recently added questions about numbers. Play numbers quiz and see all the questions. 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 Kołodziejczykwater riddles »hard 52% 551416772173993781111167 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 Kołodziejczykmathematics riddles »very hard 25% the OH − ion concentration is smaller than the H+ ion concentrationthe OH − ion concentration is smaller than the H+ ion concentration481the OH − ion concentration is greater than the H+ ion concentrationthe OH − ion concentration is greater than the H+ ion concentration368the OH − ion concentration is equal of the H+ ion concentrationthe OH − ion concentration is equal of the H+ ion concentration540Such solution doesn't existSuch solution doesn't exist530 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 Kołodziejczykgeometry riddles »hard 57% 3/4π cm33/4π cm314414/3π cm34/3π cm341174,3π cm34,3π cm3744It isn't possible to calculateIt isn't possible to calculate848 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 Kołodziejczykmathematics riddles »very easy 83% 4410988898665897Not enough dataNot enough data174 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.orgmathematics riddles »hard 52% 1/31/352560,30,343833%33%992Both answers 1/3 and 33% are correctBoth answers 1/3 and 33% are correct3303 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 TamangSouth Korea riddles »hard 50% 331342443139121213914040378 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 Tamangmath riddles »average 66% 238829902388299097216769023167690237198383772963837729691411723835117238351722 Which of the following Roman numerals stands for 4?Both IV and IIII. Both notations are correct and historically Roman numerals were often written less consistently than today. The notation 'IIII' is often seen on clock faces. The reason for that may be practical, to avoid confusing the IV and VI when the clock is held upside down (although other theories also exist).Created by: globalquiz.organcient Rome riddles »very hard 28% IVIV2342IIIIIIII40Both IV and IIIIBoth IV and IIII967None of the aboveNone of the above54 Which pH number describes a substance that is neither acidic nor alkaline?PH 7. Solutions with a pH value below 7.0 are considered acidic, whereas solutions with pH values above 7.0 are basic.Created by: Cleochemistry riddles »easy 70% pH 0pH 01833pH 7pH 76790pH 10pH 10410pH 0.5pH 0.5578 Typically, how many leap years are in a century?24. The Gregorian Calendar omits 3 leap days every 400 years, omitting February 29 in the 3 century years (integer multiples of 100) that are not also integer multiples of 400. For example, 1600 was a leap year, but 1700, 1800 and 1900 were not. Similarly, 2000 was a leap year, but 2100, 2200, and 2300 will not be.Created by: ex-terminatorcalendar riddles »hard 43% 20209492424423625254130100100439 Play mathematics quiz and see all the questions.