14/02/2018 4:33 pm
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Number system
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Post your questions related to fractions in this sub-topic. 👍
This topic was modified 6 months ago by TathaGat
7 questions & discussions are there under this sub-topic
1
17/11/2020 4:27 pm
How many 5-digit numbers can be formed with the first digit as 1 and last digit as 5, which are not divisible by 3?
a)300 b)600 c)666 d)667
This post was modified 4 years ago 2 times by Amrita Mirchandani
TG Team 20/11/2020 10:30 pm
@amritamirchandani
The divisibility rule of 3 says that the sum of digits should be divisible by 3.
1abc5
1 + 5 + a + b + c i. e
6 + a + b + c should be a multiple of three.
Or we can say three digit number abc should be divisible by 3. Hence from 000 , 003 , 006 , ....., 999 . abc can take 334 values. So 1000 -334 = 666 such numbers.
0
20/06/2018 12:24 pm
Natural numbers from 1 to n are written on board.One of the numbers was erased and the new average becomes 600/17. Find the erased number ?
Anu 02/06/2024 4:21 pm
Ans: 69
If there were n numbers before, then now there will n-1 numbers left.
Now, if average is 600/17, that means n-1 is multiple of 17.
With Hit & Trial, I come out with n-1=68 as the sum will be 69X70/2=2415.
And as per average, sum of n-1 numbers will be: (600/17)X68=2400.
Therefore, missing number is 2415-2400=15.
0
17/11/2020 4:24 pm
How many integers, greater than 999 but not greater than 4000, can be formed with the digits 0, 1, 2, 3 and 4, if repetition of digits
is allowed?
(a) 499 (b) 500 (c) 375 (d) 376 (e) 501
0
21/04/2024 3:34 pm
7/9 of the people present in a hall are sitting in 9/13 of the chairs available and the rest are standing. If there are 28 empty chairs, how many chairs would have been still empty if everyone in the hall was sitting?
1. 15 2. 12 3. 18 4. 10
0
18/05/2024 2:41 pm
In a fraction, if 2 is subtracted from the numerator as well as the denominator, then the new fraction becomes 3/4 while if 4 is added to both the numerator and the denominator, then the new fraction becomes 5/6. If the original fraction is a/b where both a and b are coprime to each other, then what is the sum of denominator and numerator?
1. 16
2. 21
3. 25
4. 29
0
02/06/2024 4:14 pm
The sum of the reciprocals of four different natural numbers is 1.85. Which of the following could be the sum of the four numbers?
TathaGat 02/06/2024 4:14 pm
1.85 can be split into
1.000 1
+.500 1/2
+.25 1/4
+.1 1/10
--------
1.85
Hence 1+2+4+10=17
