Number System The average of 7 numbers is 15, that of the first three is 6 and that of the last three is 23. What is the fourth number? 18 15 13 7 18 15 13 7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4th No. = (Total of 7 Nos) - (Total of first three + total of last 3) = (15 x 7) - (6 x 3 + 23 x 3) = 105 - (18 + 69) =105 - 87 = 18
Number System The digit in unit's place of a three digit number is thrice the digit in ten's place & the digit in hundred's place is two-third of the digit in ten's place. If the sum of three digits of number is 14 215 239 211 221 215 239 211 221 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the ten's digit be x.∴ Unit's digit = 3xHundered's digit = 2x/3∴ x + 3x + 2x/3 = 14= 3x + 9x + 2x = 14 x 3= 14x = 14 x 3= x = 3∴ Number = 239
Number System What is the sum of the local values of the digits 2, 3, 4, 5 in the number 2345? 2435 2105 5243 2345 2435 2105 5243 2345 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2000 + 300 + 40 + 5 = 2345
Number System If a number is subtracted from its square we get 272. Find the number? 14 17 24 22 14 17 24 22 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x2 – x = 272 => x =17
Number System How many numbers between 300 and 800 can be by using digits 2, 4, 5, 6 and 0 ? 48 36 52 56 48 36 52 56 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ∴ Reqd . numbers = 3 x 4P2 = 3 x 12 = 36
Number System The sum of the ages of a son and father is 65 years. After 5 years the age of father will be double of the age of son. What is the age of son ? 17 years 19 years 20 years 18 years 17 years 19 years 20 years 18 years ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the age of the son be x and the age of the father be y.Therefore, x + y = 65 ..........(i)or, 2 x (x + 5) = (y + 5)or, 2x + 10 = y + 5or, 2x - y = 5 ...................(ii)From equations (i) and (ii), x = 20, y = 45
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