Elitmus
Exam
Numerical Ability
Number System
In a party, there are rows arranged with 12,20 and 30 chairs and there were 3 left in all the cases. When there
were 11 rows. There were no chair left. If 30 chairs were added. Then what will be the reminder?
Read Solution (Total 4)
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- Ans - 8
Let the total number of chairs be x.
Given that, x divided by 11 leaves remainder zero and x divided by 12, 20 and 30 each leaves 3 as a remainder.
So, the main concern is to find the number (x) which gets divided by 11 and at the same time leaves remainder 3 when divided by 12, 20 and 30.
Thus, it can be done by finding the LCM of 12, 20 and 30 and getting that multiple of LCM which when added 3 gets divided by 11 completely.
i.e. LCM (12, 20 and 30) = 60
And the multiple of 60 which when added 3 gets divided by 11 completely is 360.
Thus, x = 360 + 3 = 363.
Now, adding 30 more chairs
i.e. x + 30 = 393.
Hence, 393 when divided by 11 leaves 8 as a remainder. - 7 years agoHelpfull: Yes(9) No(0)
- LCM of 12,20,30 is 120.so the number is in the form of 120x+3 which is divisible by 11,by placing x=3, we get 363 which is divisible by 11 and the multiple of 120 when 3 is subtracted from 363.so the no. is 363.so when 30 is added to it and is divided by 11 we get remainder as 8
- 8 years agoHelpfull: Yes(6) No(6)
- Broah first of all the lcm of 12, 20, 30 is 60 not 120
- 8 years agoHelpfull: Yes(5) No(2)
- Mr. Rohit Yadav.. Ans will be same if you take 60 or 120 or 240 ..... they all are the LCM of 12,20,30.
- 2 years agoHelpfull: Yes(1) No(0)
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