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Home › Grade7 › Grade 7 Olympiad › Math Olympiad-Grade-7 › HCF, LCM & Factorisation › HCF and LCM Worksheet-3

HCF and LCM Worksheet-3

HCF and LCM Worksheet-3

 

Mark against the correct answer:

  1. The L.C.M. of two numbers is 495 and their H.C.F. is 5. If the sum of the numbers is 10, then their difference is :

(a) 10                  (b) 46                 (c) 70                  (d) 90

 

  1. The product of the L.C.M. and H.C.F. of two numbers is 24. The difference of two numbers is 2. Find the numbers.

(a) 2 and 4         (b) 6 and 4        (c) 8 and 6         (d) 8 and 10

 

  1. If the sum of two numbers is 55 and the H.C.F. and L.C.M. of these numbers are 5 and 120 respectively, then the sum of the reciprocals of the numbers is equal to :

(a)                (b)               (c)               (d)

 

  1. The L.C.M. of two numbers is 45 times their H.C.F. If one of the numbers is 125 and the sum of H.C.F. and L.C.M. is 1150, the other number is :

(a) 215                (b) 220               (c) 225                (d) 235

 

  1. The H.C.F, and L.C.M. of two numbers are 50 and 250 respectively. If the first number is divided by 2. the quotient is 50. The second number is :

(a) 50                  (b) 100               (c) 125                (d) 250

 

  1. The product of two numbers is 1320 and their H.C.F. is 6. The L.C.M. of the numbers is :

(a) 220               (b) 1314              (c) 1326              (d) 7920

 

  1. Product of two co-prime numbers is 117. Their L.C.M. should be :

(a) 1                                                 (b) 117

(c) equal to their H.C.F.             (d) cannot be calculated

 

  1. The L.C.M. of three different numbers is 120. Which of the following cannot be their H.C.F. ?

(a) 8                    (b) 12                  (c) 24                  (d) 35

 

  1. The H.C.F. of two numbers is 8. Which one of the following can never be their L.C.M. ?

(a) 24                  (b) 48                 (c) 56                  (d) 60

 

  1. 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

 

  1. About the number of pairs which have 16 as their H.C.F. and 136 as their L.C.M. we can definitely say that :

(a) no such pair exists                 (b) only one such pair exists

(c) only two such pairs exist      (d) many such pairs exist

 

  1. The H.C.F. and L.C.M. of two numbers are 11 and 385 respectively. If one number lies between 75 and 125, then that number is :

(a) 77                  (b) 88                 (c) 99                  (d) 110

 

  1. Two numbers, both greater than 29, have H.C.F. 29 and L.C.M. 4147. The sum of the numbers is :

(a) 666               (b) 669               (c) 696               (d) 966

 

  1. L.C.M. of two prime numbers x and y (x > y) is 161. The value of 3y – x is :

(a) –2                 (b) –1                  (c)  1                    (d) 2

 

  1. The greatest number that exactly divides 105, 1001 and 2436 is :

(a) 3                    (b) 7                    (c) 11                   (d) 21

 

  1. The greatest possible length which can be used to measure exactly the lengths 7 m, 3 m 85 cm, 12 m 95 cm is :

(a) 15 cm            (b) 25 cm           (c) 35 cm           (d) 42 cm

 

  1. Three different containers contain 496 litres, 403 litres and 713 litres of mixtures of milk and water respectively. What biggest measure can measure all the different quantities exactly ?

(a) 1 litre            (b) 7 litres          (c) 31 litres        (d) 41 litres

 

  1.  The maximum number of students among them 1001 pens and 910 pencils can be distributed in such a way that each student gets the same number of pens and same number of pencils is :

(a) 91                  (b) 910               (c) 1001              (d) 1911

 

  1. A rectangular courtyard 3.78 metres long and 5.25 metres wide is to be paved exactly with square tiles, all of the same size. What is the largest size of the tile which could be used for the purpose ?

(a) 14 cms          (b) 21 cms         (c) 42 cms         (d) None of these

 

  1. Find the greatest number that will divide 43, 91 and 183 so as to leave the same remainder in each case.

(a) 4                    (b) 7                    (c) 9                    (d) 13

 

Answer Key:

(1)-(a); (2)-(b); (3)-(c); (4)-(c); (5)-(c); (6)-(a); (7)-(b); (8)-(d); (9)-(d); (10)-(c); (11)-(a); (12)-(a); (13)-(c); (14)-(a); (15)-(b); (16)-(c); (17)-(c); (18)-(a); (19)-(b); (20)-(a)