Number System Which one of the following is the sum of the numbers 1, 3, 5, 7, 9…. up to nth number? N(N + 1)/2 N2 N(N + 1) N2 + 1 N(N + 1)/2 N2 N(N + 1) N2 + 1 ANSWER DOWNLOAD EXAMIANS APP
Number System The difference between 35% of a number and 18% of the same number is 93.5 then what is the 40% of that number ? 232 245 220 225 232 245 220 225 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Diff = (35 - 18)% of x = 93.517x/100 = 93.5Therefore, x = 550Therefore, 40% of 550 = 220
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 ? 39/340 45/340 51/340 58/340 39/340 45/340 51/340 58/340 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 The sum of the two digits of a two-digit number is 15 and the difference between the two digits of the two digit number is 3. What is the product of the two digits of the two digit number ? 36 14 54 None of these 36 14 54 None of these ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10 x + yWhere x > yAccording to the question,x + y = 15 and x - y = 3Solving both the equations,x = 9, y = 6∴ x x y = 9 x 6 = 54
Number System In how many different ways can the letters of word "SENTENCE" be arranged ? 6460 3360 2360 3260 6460 3360 2360 3260 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Number of ways = 8!/3! 2! = 40320/12 = 3360
Number System Find the number, when 15 is subtracted from 7 times the number, the result is 10 more than twice of the number 4 5 15 7.5 4 5 15 7.5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.7x -15 = 2x + 10 => 5x = 25 => x = 5
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