a2zinterviews

31.	A two digit number exceeds the sum of the digits of that number by 18. If the digit at the unit's place is double the digit in the ten's place, what is the number?
	A.  12
	B.  24
	C.  42
	D.  48

Solution

Let the ten's digit be x. Then, unit's digit = 2x. Number = 10x + 2x = 12x; Sum of digits = x + 2x = 3x. Therefore 12x - 3x = 18 ‹=› 9x = 18 ‹=› x = 2. Hence, required number = 12x = 24.

32.	The difference between two integers is 5. Their product is 500. Find the numbers.
	A.  15, 20
	B.  20, 25
	C.  30, 25
	D.  21, 26

Solution

Let the integers be x and (x+5). Then, x(x+5) = 500 ‹=›x2 + 5x - 500 = 0 ‹=›(x + 25)(x - 20) = 0 ‹=›x = 20. So, the numbers are 20 and 25.

33.	Three numbers are in the ratio of 4 : 5 : 6 and their average is 25. The largest number is
	A.  20
	B.  25
	C.  30
	D.  40

Solution

Let the numbers be 4x, 5x and 6x. Then, 4x + 5x + 6x / 3 = 25 ‹=›5x = 25 ‹=›x = 5. Therefore Largest number = 6x = 30.

34.	The sum of four consecutive even integers is 1284. The greatest of them is
	A.  320
	B.  322
	C.  324
	D.  326

Solution

Let the four integers be x, x + 2, x + 4, x + 6. Then, x + (x + 2) + (x + 4) + (x + 6) = 1284 ‹=›4x = 1272 ‹=›x = 318. ‹=›Greatest number = x + 6 ‹=›324.

35.	The sum of three consecutive multiples of 3 is 72. What is the largest number?
	A.  21
	B.  24
	C.  25
	D.  27

Solution

Let the numbers be 3x, 3x + 3 and 3x + 6. Then, 3x + (3x + 3) + (3x + 6) = 72. ‹=›9x = 63. ‹=›x = 7. Therefore, Largest number = 3x + 6 = 27.