Number System What is the sum of 1 + 2 + 3+ ... + 27 ? 382 343 396 378 382 343 396 378 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Sum = 27 x (27 + 1)/2= 27 x 28/2= 27 x 14= 378
Number System (√6 + 1)² = ? + 2√6 8 5 7 6 8 5 7 6 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = (√6 + 1)² - 2√6= (√6)² + 2 x √6 + 1 + 1² - 2√6= 6 + 2√6 + 1 - 2√6 = 6 + 1 = 7
Number System What number should come in the place of (?) in the following number series ? 1, 4, 9, 25, 49, ?, 169, 289, 361 121 321 225 11 121 321 225 11 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The series is (Prime No.)²So it is (11)² = 121
Number System By how much is 3/5th of 875 greater than 2/3 of 333? 362 199 303 233 362 199 303 233 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 3/5th of 875 is greater than 2/3rd of 333= 3/5 * 875 - 2/3 * 333= 525 - 222 = 303.
Number System If a + b = 16 and ab = 68, what is the value of a² + b² ? 124 120 116 112 124 120 116 112 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP a + b = 16 Therefore, (a+b)² = (16)² = 256 a² + b² + 2ab = 256Therefore, a² + b² = 256 - 2 x 68Therefore, a² + b² = 256 - 136 = 120
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1955 1945 1965 1975 1955 1945 1965 1975 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Because (x + y)² = x² + y² + 2xy∴ x² + y² = (x + y)² - 2xy∴ x² + y² = (61)² - 2 x 888= 3721 - 1776 = 1945
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