LCM & HCF-10

If x : y be the ratio of two whole numbers and z be their HCF, then the LCM of those two numbers is

• YZ

• XZ/Y

• XY/Z

• XYZ

The sum of the H.C.F. and L.C.M of two numbers is 680 and the L.C.M. is 84 times the H.C.F. If one of the number is 56, the other is :

• 84

• 12

• 8

• 96

If A and B are the H.C.F. and L.C.M. respectively of two algebraic expressions x and y, and A + B = x + y, then the value of A3 + B3

is

• x^3 – y^3         

• x^3       

• y^3       

• x^3+ y^3

If P = 2^3 3^10 5 ; Q = 2^5 3 7, then  HCF of P and Q is :

• 2.3.5.7      

• 3.2^3      

• 2^2.3^7

• 2^5 3^10 5 * 7

The HCF (GCD) of a, b is 12, a, b are positive integers and a > b > 12. The smallest values of (a, b) are respectively

• 12,24

• 24,12

• 24,36

• 36,24

The least number to be subtracted from 36798 to get a number which is exactly divisible by 78 is

• 18

• 20

• 38

• 60

A fraction becomes 1/6 when 4 is subtracted from its numerator and 1 is added to its denominator. If 2 and 1 are respectively added to its numerator and the denominator, it becomes 1/3. Then, the LCM of the numerator and denominator of the said fraction, must be

• 14

• 350

• 5

• 70

The number between 4000 and 5000 that is divisible by each of 12, 18, 21 and 32 is

• 4023

• 4032

• 4302

• 4203

A number between 1000 and 2000 which when divided by 30, 36 and 80 gives a remainder 11 in each case is

• 1451

• 1641

• 1712

• 1523

Let N be the greatest number that will divide 1305, 4665 and 6905 leaving the same remainder in each case. Then, sum of the digits in N is :

• 4

• 5

• 6

• 8