Number System How many numbers between 300 and 800 can be by using digits 2, 4, 5, 6 and 0 ? 56 52 48 36 56 52 48 36 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ∴ Reqd . numbers = 3 x 4P2 = 3 x 12 = 36
Number System The difference between the two digit number and the number obtained by interchanging its digits is 54. The difference between the digits is? 4 6 1 Nothing can be said. 4 6 1 Nothing can be said. ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (10x + y) – (10y + x) = 54x – y = 6
Number System If the fraction 8/6, 7/5, 18/13, 9/5 and 7/11 are arranged in descending order of their values, which one will be the second ? 3/4 2/7 7/5 1/9 3/4 2/7 7/5 1/9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 8/6 = 1. 333, 7/5 = 1.4, 18/13 = 1.3849/5 = 1.8 and 7/11 = 0.636Therefore, Descending order is 9/5 > 7/5 > 18/13 > 8/6 > 7/11Therefore Second fraction is 7/5
Number System A bag contains four red, six black and seven green balls. Three balls are drawn randomly. What is the probability that the balls drawn contain exactly two red balls ? 58/340 45/340 51/340 39/340 58/340 45/340 51/340 39/340 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total balls = 4 + 6 + 7 = 17∴ n(S) = 17C1 = 680Two red balls can be selected from four red balls in 4C2 = 6 ways.and the third ball can be selected from the remaining 13 balls in 13C1 = 13 ways.∴ P (E) = 13x6/680 = 39/340
Number System √360 - 225 x 2 + 379 = ? 19 18 17 20 19 18 17 20 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = √360 - 225 x 2 + 379 = √360 - 450 + 379 = √289= 17
Number System If a number is subtracted from its square we get 272. Find the number? 14 24 17 22 14 24 17 22 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x2 – x = 272 => x =17
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