Number System If one-third of one fourth of a number is 15, then three-tenth of that number is: 45 25 35 54 45 25 35 54 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,1/3 of 1/4 of x = 15x = 15 * 12 = 180So, required number = (3/10 * 180) = 54.
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 ? 51/340 58/340 45/340 39/340 51/340 58/340 45/340 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 ?2704 x ?2209=? 3444 4444 2444 1444 3444 4444 2444 1444 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2444
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 15 13 18 7 15 13 18 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 The sum of three consecutive multiples of 3 is 72. What is the largest number? 36 27 24 21 36 27 24 21 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be 3x, 3x + 3 and 3x + 6.Then,3x + (3x + 3) + (3x + 6) = 729x = 63x = 7Largest number = 3x + 6 = 27.
Number System 75% of 250 - ?% of 380 = 54.5 35 33 31 39 35 33 31 39 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 250 x 75/100 - 380 x ?/100 = 54.5= 250 x 75 - 380 x ?= 54.5 x 100= 18750 - 380 x ?= 5450= 380 x? = 18750 - 5450= 13300= ? = 13300/380 = 35
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