While Preparing for Quantitative aptitude tests, questions on Number system- HCF and LCM are asked frequently.
Top 10 HCF and LCM Questions
Q1) Two numbers are in the ratio 2 : 3. If their L.C.M. is 48. what is sum of the numbers?
A) 64
B) 42
C) 28
D) 40
Solution :
Q2) What is the greatest number of four digits which is divisible by 15, 25, 40 and 75 ?
A) 9200
B) 9600
C) 9800
D) 9400
Solution :
Q3) Three numbers are in the ratio of 2 : 3 : 4 and their L.C.M. is 240. Their H.C.F. is:???????
A) 40
B) 20
C) 10
D) 30
Solution :
Q4) What is the lowest common multiple of 12, 36 and 20?
A) 120
B) 160
C) 220
D) 1
Solution :
Q5) H.C.F. of 513, 1134 and 1215 is _____________
A) 18
B) 27
C) 33
D) 36
Solution :
We know different methods to calculate H.C.F.
Finding H.C.F. by division method:
H.C.F. of 513, 1134 and 1215 = 3 × 3 × 3 = 27.
Q6) The greatest number which on dividing 1657 and 2037 leaves remainders 6 and 5 respectively, is:
A) 127
B) 305
C) 235
D) 123
Solution :
Required number = H.C.F. of (1657 - 6) and (2037 - 5)
= H.C.F. of 1651 and 2032 = 127.
Q7) The H.C.F. of two numbers is 23 and the other two factors of their L.C.M. are 13 and 14. The larger of the two numbers is:
A) 276
B) 299
C) 322
D) 345
Solution :
Clearly, the numbers are (23 x 13) and (23 x 14).
Larger number = (23 x 14) = 322.
Q8) HCF of 3/16, 5/12, 7/8 is:
A) 2/47
B) 3/47
C) 1/48
D) 5/48
Solution :
HCF of numerators = 1
LCM of denominators = 48
=> 1/48
Q9) The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 8 is:
A) 544
B) 548
C) 504
D) 536
Solution :
Required number = (L.C.M. of 12, 15, 20, 54) + 8 = 540 + 8 = 548.
Q10) Find the lowest common multiple of 24, 36 and 40.
A) 120
B) 240
C) 360
D) 480
Solution :
