Number System What should come in the place of ' ? ' in the following number series ? 2, 5, 9, 19, 37, ? 78 75 76 77 78 75 76 77 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2 x 2 + 1 = 5;5 x 2 - 1 = 99 x 2 + 1 = 19: 19 x 2 - 1 = 3737 x 2 + 1 = 75
Number System If a + b = 16 and ab = 68, what is the value of a² + b² ? 124 116 112 120 124 116 112 120 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 how many different ways can the letters of the word 'FRUGAL'be arranged ? 720 556 660 515 720 556 660 515 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In FRUGAL there ae six difference letters Therefore, 6 ! = 6 x 5 x 4 x 3 x 2 x 1 = 720
Number System The difference between a two-digit number and the number obtained after interchanging its two digits is 36. The sum of the two digits of the number is 12. Find the lowest such possible number. 47 48 49 50 47 48 49 50 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the digits be x and yTherefore, x + y = 12 .............(1)(10y + x) - (10x + y) Therefore, y - x = 4............. (2)Solving (1) and (2), y = 8 Therefore, x = 4There are two possible numbers 48 and 84. So the lowest no. is 48.
Number System The difference between 72% of a number and 49% of the same number is 575. What is 9% of that number ? 295 245 225 275 295 245 225 275 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be x.Therefore, 72% of x - 49% of x = 575Therefore, (72 - 49)% of x = 575Therefore, 9% of x = 575/23 x 9 = 225
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