Number System Simplify the 121 * 175 + 363 * 275 328100 363000 316600 None of these 328100 363000 316600 None of these ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 121 * 175 + 363 * 275 => 121 * 175 + 121 * 3 * 275121 * 175 + 121 * 825= 121 * (175 + 825) = 121000
Number System {3√4913}² = ? 225 121 333 289 225 121 333 289 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = (3√4913)² = (17)² = 289
Number System The average of 7 numbers is 15, that of the first three is 6 and that of the last three is 23. What is the fourth number? 7 18 15 13 7 18 15 13 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4th No. = (Total of 7 Nos) - (Total of first three + total of last 3) = (15 x 7) - (6 x 3 + 23 x 3) = 105 - (18 + 69) =105 - 87 = 18
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 ? 45/340 51/340 58/340 39/340 45/340 51/340 58/340 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 What should come in the place of ' ? ' in the following number series ? 2, 5, 9, 19, 37, ? 76 78 77 75 76 78 77 75 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2 x 2 + 1 = 5;5 x 2 - 1 = 99 x 2 + 1 = 19: 19 x 2 - 1 = 3737 x 2 + 1 = 75
Number System If the numerator of a fraction is decreased by 12.5% and the denominator is increased by 180% the resultant fraction is 1/2. What is the original fraction ? 8/5 1/5 3/5 7/5 8/5 1/5 3/5 7/5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the original fraction be x/y.∴ x x 87.5/100/y x 280/100 = 1/2or 87.5x/280y = 1/2∴ 175x = 280y∴ x/y = 280/175 = 8/5
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