Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2520 2678 2367 2410 2520 2678 2367 2410 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System The sum of five consecutive numbers is 190. What is the sum of the largest and the smallest number ? 74 73 76 75 74 73 76 75 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x + x + 1 + x + 2 + x + 3 + x + 4= 190= 5x + 10 = 190= 5x = 190 - 10 = 180= x = 180/5 = 36The largest number = 36 + 4 = 40∴ Required sum = 36 + 40 = 76
Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 180 28 12 160 180 28 12 160 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, x + y = 20 and x - y = 8x2 - y2 = (x + y)(x - y) = 20 * 8 = 160.
Number System What is the sum of all the prime numbers from 20 to 40? 120 118 117 119 120 118 117 119 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 23 + 29 + 31 + 37 = 120
Number System If a + b = 16 and ab = 68, what is the value of a² + b² ? 116 124 120 112 116 124 120 112 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 In an examination, 68% of the total examinees passed. If the number of failures is 248, the total number of examinees is 640 750 775 725 640 750 775 725 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Failed students are 32% which is 248.∴ Total = 24800/32 = 775
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