數學H.C.F&L.C.M(唔一定要做曬)

A) Find the H.C.F of each of the following groups of numbers.

Q1. 45, 105

(i)Factors of 45 are 1,___,___,___,___,___
(ii)Factors of 105 are 1,3,7___,___,___,___,___
(iii)Common factors of 45 and 105 are 1,___,___,___
(iv)H.C.Fof 45 and105 is____.

Q2.8,12,30

(i)Factors of 8 are 1,___,___,___
(ii)Factors of 12 are 1,___,___,___,___,___
(iii)Factors of 30 are1,2,___,___,___,___,___,___
(iv)Common factors of 8,12 and 30 are___,___
(v)H.C.F of 8,12 and 30 is____.

B)Find the L.C.M of each of the following groups of numbers.

Q1. 28,42

(i)Mulitiples of 28 are 28,_14__,_7__,_4__,_2__,__1_
(ii)Multiples of 42 are 42,__21_,__14_,7,__6_,_3__,_2__,__1_
(iii)Common munltiples of 28 and 42 are_7__,__2_,__1_
(iv)L.C.M of28 and 42 is_168___.

Q2. 20,24,30

(i)Mulitiples of 20 are 20,_10__,__5_,_4__,_2__,_1__
(ii)Multiples of 24 are 24,_12__,__8_,__6_,_4__,__3_,_2__,1
(iii)Multiples of 30 are 30,_15__,_10__,__6_,__5_,__3_,2,1
(iv)Common munltiples of 20,24 and 30 are_1__,__2_
(v)L.C.M of 20,24 and 30 is _120___.


C)

Q1.108sweets and 88 chocolates are to be shared among some children. If each child gets the same number of sweets and chocolates, how many sweets and chocolates each child gets the least?(Hint:Find the largest number of children first)
multiples of 108:1,2,3,4,6,9,12,18,27,36,54,108
multiples of 88:1,2,,4,8,11,22,44,88
hcf of 108 &88 =4
there are 4 children
each child gets 108/4=27 candies and 88/4=22 chocolates

(i)Factors of 45 are (1), (3), (5), (9), (15), (45)
(ii)Factors of 105 are (1), (3), (5), (7), (15), (21), (35), (105)
(iii)Common factors of 45 and 105 are (1), (3), (5), (15)
(iv)H.C.Fof 45 and105 is (15).

Question 2
(i)Factors of 8 are (1), (2), (4), (8)
(ii)Factors of 12 are (1), (2), (3), (4), (6), (12)
(iii)Factors of 30 are (1), (2), (3), (5),(6), (10), (15), (30)
(iv)Common factors of 8,12 and 30 are(1), (2)
(v)H.C.F of 8,12 and 30 is(2).

B)
Question 1
(i)Mulitiples of 28 are (28), (56), (84),(112)...
(ii)Multiples of 42 are (42), (84), (126), (168)
(iii)Common multiples of 28 and 42 are(84),(168), (252)
(iv)L.C.M of 28 and 42 is(84).

Question 2
(i)Mulitiples of 20 are 20,(40), (60), (80), (120), (140), (160), (180)...
(ii)Multiples of 24 are 24,(48), (72), (96), (120), (144)...
(iii)Multiples of 30 are 30,(60), (90), (120), (160)...
(iv)Common munltiples of 20,24 and 30 are(120), (240)
(v)L.C.M of 20,24 and 30 is (120).

C)
Q1.108 sweets and 88 chocolates are to be shared among some children. If each child gets the same number of sweets and chocolates, how many sweets and chocolates each child gets the least?(Hint:Find the largest number of children first)

Solution:
1. Find out the common factor between 88 and 108.
Factors of 88: (1), (2), (4), (8), (11), (22), (44), (88)
Factors of 108: (1), (2), (3), (4), (6), (9), (12), (18), (27), (36), (72), (108)
2. And you get the answer is 4.

Those answers are not be supposed its accuratcy.
Hope I can help you.