Number System Which one of the following represents the sum of the first n even numbers? N(N + 1) N2 N2+ 1 N(N – 1) N(N + 1) N2 N2+ 1 N(N – 1) ANSWER EXPLANATION DOWNLOAD EXAMIANS APP N (N + 1)
Number System In an examination, 68% of the total examinees passed. If the number of failures is 248, the total number of examinees is 640 775 750 725 640 775 750 725 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Failed students are 32% which is 248.∴ Total = 24800/32 = 775
Number System In a fraction, twice the numerator is two more than the denominator. If 3 is added to the numerator and the denominator each, then the resultant fraction will be 2/3 .What was the original fraction 17/12 19/12 7/12 11/12 17/12 19/12 7/12 11/12 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 7/12
Number System The average of 7 consecutive even numbers A, B, C, D, E, F and G is 36. What is the product of ' C and 'E' ? 1168 1468 1327 1292 1168 1468 1327 1292 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP A + B + C + D + E + F + G/7 = 36Therefore, D = 36Therefore, C = 34, E = 38Therefore, Product = 34 x 38 = 1292
Number System The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is: 5/4 3/5 4/5 3/10 5/4 3/5 4/5 3/10 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 1/x - x = 9/20 20x2 + 9x - 20 = 0 20x2 + 25x - 16x - 20 = 0 5x(4x + 5) -4(4x + 5) = 0(4x + 5)(5x - 4) = 0x = 4/5
Number System (3² x 4² x 5) ÷ 36 = (?)² - 80 12 10 16 14 12 10 16 14 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 3² x 4² x 5/36 + 80= 20 + 80 = 100∴ ? = √100 = 10
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