Quiz-1

LCM + HCF = 1884..(1)
LCM -  HCF = 1860..(2)
Let the numbers be x & y,
x - y =12
x= y + 12
We know,
x . y = HCF*LCM
y(y + 12) = HCF* LCM
y² + 12 y = 12*1872

y² + 12y - 22464 = 0
y = 144 or -156
We discard the negative answer
y =144
x = 156
x + y =300

Let the numbers be 2x, 3x and 4x
LCM of 2x, 3x and 4x = 12x
12 x = 240
⇒x=240 / 12 = 20
H.C.F of 2x, 3x and 4x = x = 20
correct option is c

HCF of fractions = HCF of Numerator/LCM of Denominator



= HCF of 7, 35/LCM of 2, 4



= 7*1/2*2



= 7/4



H.C.F of 2x, 3x and 4x = x = 20

Correct Option: C

Solution:

Alloy 1 is 70 Kg and contains copper and zinc in the ratio of 3:4

Copper = 70*3/7 =30 kg and Zinc = 70*4/7 = 40 Kg

alloy 2 which is 20 Kg ; contains zinc and tin in ratio of 2;3.

Zinc = 20*2/5=8 kg and tin = 20*3/5 = 12 Kg

Hence after mixing both alloys total Quantity of Zinc becomes 40+8 = 48 Kg

HCF + LCM = Sum of two numbers.



14+X = 42 therefore X = 42-14 = 28 



Hence LCM = 28

Solution:  The HCF of 4199 and 4693 is B (247). The shortest and fastest way to get the HCF is on dividing and larger number with the small number, i.e, dividing 4693 with 4199. The remainder is then used as quotient to divide 4199. The remainder thus received is again used as quotient to divide the previous quotient. This process goes on till we get a zero as remainder. The last quotient is the final answer.