## LCM and HCF

#### LCM and HCF

1. What is the greatest number that divides 263, 935 and 1383 leaving a remainder of 7 in each case ?

1. The required greatest number is the HCF of 263-7, 935-7, 1383-7

##### Correct Option: C

The required greatest number is the HCF of 263-7, 935-7, 1383-7
i.e. 256, 928 and 1376 HCF = 32

1. If (x+2) is the HCF of x2 + ax + b and x2 + cx + d , then which one of the following is correct ?

1. If (x+2) is the HCF of x2 + ax + b and x2 + cx + d.
Then, (-2)2 -2a +b = (-2)2 -2c + d

##### Correct Option: C

If (x+2) is the HCF of x2 + ax + b and x2 + cx + d.
Then, (-2)2 -2a +b = (-2)2 -2c + d
b + 2c = 2a + d

1. Find the greatest possible length which can be used to measure 4m 3cm, 4m 34cm and 4m 65cm exactly.

1. Required measure = HCF of 403, 434 and 465

##### Correct Option: A

Required measure = HCF of 403, 434 and 465
= 31 cm

1. Which of the following fractions is the greatest of all ? 7/8, 6/7, 4/5, 5/6 ?

1. 7 / 8 = 0.875,
6 / 7 = 0.857,
4 / 5 = 0.8 and 5/6 = 0.833
Now, 0.875 > 0.857 > 0.833 > 0.8
So, 7/8 is the greatest

##### Correct Option: D

7 / 8 = 0.875,
6 / 7 = 0.857,
4 / 5 = 0.8 and 5/6 = 0.833
Now, 0.875 > 0.857 > 0.833 > 0.8
So, 7/8 is the greatest

1. L.C.M of 2/3, 4/9, 5/6 and 7/12 is ?

1. L.C.M = ( L.C.M . of 2, 4, 5, 7) / (H.C.F. of 3, 9, 6, 12)

##### Correct Option: D

L.C.M = ( L.C.M . of 2, 4, 5, 7) / (H.C.F. of 3, 9, 6, 12)
= 140/3