Number System If the difference between a number and two-fifths of that number is 45 what is the number ? 77 75 76 78 77 75 76 78 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x ∴ x - 2x/5 = 45∴ x = 75
Number System A basket contains eight white and ten black balls. Two draws of one ball each are made without replacement. What is the probability that one ball is white and the other ball is black ? 80/153 80/150 80/151 80/152 80/153 80/150 80/151 80/152 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Two balls can be drawn from 18 balls in 18C2 Ways, ie 153 ways. One white from 8 white balls can be drawn in 8C1 = 8 ways and one black ball from 10 black can be drawn in 10C1 = 10 ways.∴ n(S) = 153, n(E) = 8 x 10 = 80∴ P(E) = 80/153
Number System If (83)² is subtracted from the square of a number, the answer so obtained is 8487. What is the number ? 163 146 179 124 163 146 179 124 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x Therefore, x² - (83)² = 8487x² = 8487 + (83)²x² = 8487 + 6889x² = 15376Therefore, x² = 15376 x = 124
Number System The difference of two numbers is 1365. On dividing the larger number by the smaller, we get 6 as quotient and 15 as remainder. What is the smaller number? 240 270 360 295 240 270 360 295 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the smallest number be x.Then larger number = (x + 1365)x + 1365 = 6x + 15= 5x = 1350 x = 270Smaller number = 270.
Number System If a number is multiplied by. three-fourth of itself, the value thus obtained is 10800. What is that number ? 180 60 260 120 180 60 260 120 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x x 3x/4 = 10800= x² = 10800 x 4/3 = 14400∴ x = √14400 = 120
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