Elitmus
Exam
Numerical Ability
Number System
The digital sum of no is given as 1994 ie [1+9+9+4 = 23 then 2+3 =5]
unless we get a unit digit,
Find the number of perfect squares obtained in the digital sum from 2000 to 2199
optns r
22 42 16 nd may be d optns may be wrong but d ques is same
Read Solution (Total 9)
-
- Ans is 66
There are only 3 single digit perfect square i.e. 1,4,9
Total no. =200(including 2000 and 2199)
when we sum 2000=2+0+0+0=2
2001=2+0+0+1=3
2002=2+0+0+2=4 and upto
2199=2+1+9+9=21=2+1=3
we see a pattern no. are going from 2,3,4---9,1,2and so on
So no. of times pattern followed= 200/9=22 and 2 as remainder
So xcept 2 and 3 each no. will come 22 times
So total no. of times=22+22+22=66
- 8 years agoHelpfull: Yes(6) No(2)
- given 2000 and 2199 then if we start adding the digits from start i.e 2000 and proceed a sequence is produced i.e difference of 5 and 4
here it goes
2002= 2+0+0+2=4(perfect square)
now
(2002) + 5 = 2007
taking 2007= 2+0+0+7=9(perfect square)
now add +4 to 2007= 2011 which is 2+0+1+1=4(perfect square again)
proceed this way... - 8 years agoHelpfull: Yes(2) No(2)
- we have to find that how many times the number which are perfect square by following digital sum rule occurs in the series 2000 to 2199
Total no. =200(including 2000 and 2199)
when we sum 2000=2+0+0+0=2
2001=2+0+0+1=3
2002=2+0+0+2=4 and upto
2199=2+1+9+9=21=2+1=3
we see a pattern no. are going from 2,3,4,5,6,7,8,9,1,2and so on
There are only 2 single digit perfect square i.e. 4,9
200/9=22 reminder as 2
so 22+22=44 - 8 years agoHelpfull: Yes(2) No(1)
- 44 is the correct answer
- 8 years agoHelpfull: Yes(1) No(3)
- but 31 and 26 are given option there.........
what should be the?........ - 8 years agoHelpfull: Yes(1) No(3)
- 66.....after doing addition using digital method i.e 2+0+0+0=2
2+0+0+1=3
.......
.....
2+1+9+9=3
....so the number starts from 2,3,4...9,1,2,......9.....1,2,3
for perfect square only 1,4,9 are there...so 2+64=66 - 8 years agoHelpfull: Yes(1) No(0)
- d.66 s the total no
- 8 years agoHelpfull: Yes(0) No(3)
- GuySs how to determine dat
any formula involved - 8 years agoHelpfull: Yes(0) No(1)
- as digital sum is single digit there are two possibilities either 4 or 9 i.e the sum of digits turn out to be 4 or 9.
now, the maximum sum of digits can be 2+1+9+9= 21.
So , we have to count all numbers whose sum of digits can be 4 or 9 (under the constraint that sum - 8 years agoHelpfull: Yes(0) No(3)
Elitmus Other Question