Number System In how many ways can 5 boys be chosen from 6 boys and 4 girls so as to include exactly one girl ? 56 54 60 58 56 54 60 58 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP One girl can be chosen in 4C1 = 4 ways and 4 boys can be chosen in 6C4 = 15 ways ∴ Total number of ways = 4 x 15 = 60 ways.
Number System What is the least number that should be added to 5200 to make it a perfect square ? 288 225 129 275 288 225 129 275 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We sec (73)² = 5329 and (72)² = 5184ie 5329 > 5200 > 5184So 129 should be added to make is perfect square.
Number System If the of a two-digit number are interchanged, the number so obtained is greater than the original number by 18. If the sum of the two digits of the number is 14. What is the original number ? 68 62 64 66 68 62 64 66 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be 10x + y.No. formed by the interchange of digits = 10y + xWe have y - x = 2 .........(i)y + x = 14 .........(ii)Solving (i) and (ii), we get x = 6, and y = 8∴ the no. is 68.
Number System The sum and the product of two numbers are 25 and 144 respectively, the difference of the number is? 7 5 3 11 7 5 3 11 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x + y = 25xy = 144(x- y)2 = (x + y)2 – 4xy(x- y)2 = 625 – 576 => (x – y) = 7
Number System The difference between 78% of a number and 59% of the same number is 323. What is 62% of that number ? Rs. 945 Rs. 986 Rs. 1054 Rs. 926 Rs. 945 Rs. 986 Rs. 1054 Rs. 926 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.78% of x - 59% of x = 323= 78x - 59x/100 = 323= 19x/100 = 323∴ x = 323 x 100/19 = 1700= 62% of 1700 = 1700 x 62/100 = 1054
Number System If 1.5 x= 0.04 y, then the value of (y-x) (y+x) is: 77/73 83/77 73/77 93/77 77/73 83/77 73/77 93/77 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 73/77
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