Quantitative Aptitude - Numbers and Algebra
- Option : B
- Explanation :
Total age = 15 x 36
After two left, total age = 15 x 36 - 2 x 28 = 540 - 56 = 484 years.
Let the age of the person who returns be x years.
Then new average = (484 +x) / 14
Now x lies between 20 and 36 (both inclusive)
New average min = (484 + 20) /14 = 36 years
And New average max = (484 +36)/14 = 520/14 = 37.14. years
- Option : A
- Explanation : I. In case all the remaining three numbers are multiples of the prime number, HCF of the group is equal to that prime number. otherwise HCF of the group is 1. Thus, I is true.
II. Case 1: Let numbers be 2, 4, 6 and 8, where 2 is only prime number, then LCM = 24.
But LCM of 4, 6 and 8 = 24.
Case 2 : Let numbers be 2, 9, 81 and 27 Then LCM = 162 and LCM of 9, 81 and 27 = 81.
Thus, LCM = 81 * 2 = 162 Hence II is not always true.
III. Let numbers be 2, 4, 6 and 8 LCM =24 and HCF = 2 Product of four numbers = 2 *4 * 6 * 8= 384
Also, 384 ≠ 24 * 2 * 2. Thus, III is not true.
where n is a positive integer?
- Option : B
- Explanation : Total red tiles initially
Total number of tiles
As number of red tiles > number of green tiles
(since room has odd number of tiles and corner tiles are red)
Hence total red tiles required to form an alternate pattern
∴ Number of green tiles removed
