Aptitude - Problems on H.C.F and L.C.M - Discussion

Discussion Forum : Problems on H.C.F and L.C.M - General Questions (Q.No. 1)
1.
Find the greatest number that will divide 43, 91 and 183 so as to leave the same remainder in each case.
4
7
9
13
Answer: Option
Explanation:

Required number = H.C.F. of (91 - 43), (183 - 91) and (183 - 43)

     = H.C.F. of 48, 92 and 140 = 4.

Discussion:
216 comments Page 5 of 22.

Pabitra Saha said:   7 years ago
Very good explanation, Thanks @Kuldeep Sharma.

Kuldeep Sharma said:   7 years ago
let the greatest number is H.

Now;

H*Quotient(Q1)+Reminder(R)= 43 -------> (1)
H*Quotient(Q2)+Reminder(R)= 91 -------> (2)
H*Quotient(Q3)+Reminder(R)= 183 -------> (3)
Now, (1)-(2), (3)-(2), (3)-(1)
H*(Q2-Q1)= 48,
H*(Q3-Q2)= 92,
H*(Q3-Q1)= 140.

So 48, 92 and 140 are completely divisible by H, that will be the HCF of these numbers.
So, the HCF of 48, 92 and 140 is 4.
(3)

Davoas said:   7 years ago
What if we have a fixed remainder.

For example take 90, 114 and 230 with remainder 6 what will be the divisor?

Anyone explain me.

Magnus Udoka said:   7 years ago
Your explanation was superb, Thanks @Prashant.

Shreekanth said:   8 years ago
Keep on dividing all the three numbers by 2 so that reminder should be the same ie
2[43 91 183]
[ 21 45 91] remainder will be 1 for all the three.

Divide again by 2.
2[21 45 91]
10 22 45 remainders will be same ie 1.

So after this, if you try to divide all three again by 2 then you get a different value for the reminder.
And hence; 2 * 2 = 4.
(1)

Pabitra Bhusan Saha said:   8 years ago
Your explanation is very easy to understand and this is the best process, Thanks @Saroja and @Sourav.

Mahima Chaurasia said:   8 years ago
In the question it is asked the remainder should be same so, Answer is option A ie 4.

43/4 remainder is 03.
91/4 remainder is 03.
183/4 remainder is 03.

Shanmukh Adari said:   8 years ago
Your explanation is fantastic, Thank you so much @Prashant.

Sixface said:   8 years ago
It's very simple guys =>

43/4=3,
92/4=3,
183/4=3.

The remainder is 3 for all divide so 4 is the correct answer.

Chary said:   8 years ago
Thanks for giving nice explanation @Prasanth.


Post your comments here:

Your comments will be displayed after verification.