Number System The average age of seven boys sitting in a row facing North is 26 years. If the average age of first three boys is 19 years and the average age of last three boys is 32 years, what is the age of the b 30 years 28 years 29 years 31 years 30 years 28 years 29 years 31 years ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Age of the fourth boy = (26 x 7 - 3 x 19 - 3 x 32) years = (182 - 57 - 96) years = 29 years
Number System The difference between the two digit number and the number obtained by interchanging its digits is 54. The difference between the digits is? Nothing can be said. 1 6 4 Nothing can be said. 1 6 4 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (10x + y) – (10y + x) = 54x – y = 6
Number System The sum of the digits of a two digit number is 12. If the new number formed by reversing the digits is greater than the original number by 54, then what will be the original number? 69 39 59 49 69 39 59 49 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 39
Number System If the fraction 8/6, 7/5, 18/13, 9/5 and 7/11 are arranged in descending order of their values, which one will be the second ? 3/4 1/9 7/5 2/7 3/4 1/9 7/5 2/7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 8/6 = 1. 333, 7/5 = 1.4, 18/13 = 1.3849/5 = 1.8 and 7/11 = 0.636Therefore, Descending order is 9/5 > 7/5 > 18/13 > 8/6 > 7/11Therefore Second fraction is 7/5
Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2520 2410 2678 2367 2520 2410 2678 2367 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System 7.8% of 12.5 + 2.5% of 161 = ? 12 5 2 9 12 5 2 9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 7.8 x 12.5/100 + 2.5 x 161/100= 0.975 + 4.025= 5
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