how many no. will be possible between 100 to 500 such that the sum of two digit is equal to the third(example -312, 2+1=3)??
a)12
b)24
c)66
d)72

• is quant question is repeat in elitmus..tell me
• 8 years agoHelpfull: Yes(28) No(1)
• ans:- 66
  just like sanjib ans
  18 no between 100-199
  17 no between 200-299 (211)
  16 no between 300-399 (312,321)
  15 no between 400-499(413,431,422)
  
  sum is 66
  
• 8 years agoHelpfull: Yes(19) No(3)
• Ans:-72
  
  100-199
  add middle digit......so there will be ...110, 121,132,143,154,165.....total 9 no.
  add last digit......101,112,123,134....total 9 no.
  so total 18 nos.
  200-299
  calculate same as before....we will get total of 18 nos.
  
  so in between 100-500
  we will get 18*4=72
• 8 years agoHelpfull: Yes(12) No(11)
• 100 - 199 : 18
  200 - 299 : 17
  300 - 399 : 16
  400 - 499 : 15
  
  Total no. 66
• 8 years agoHelpfull: Yes(10) No(0)
• for 123 total permutation 123,132,213,231,312,321
  123=6
  134=6
  145=4 because in 6 case two case 541>500 and 514>500
  156=2 because in 6 case four case 651>500 and 615>500 and 516 ,561
  167=2
  178=2
  189=2
  
  235=4
  246=4
  257=2
  268=2
  279=2
  
  347=4
  358=2
  369=2
  total=46
  and
  101,110
  202,220
  303,330
  404,440
  total=8
  121,221,112
  242,224,422
  336,363
  448,484
  total=10
  
  
  total no of case 46+8+10=66
  
• 8 years agoHelpfull: Yes(9) No(1)
• correct answer is 66
  explanation;
  a b c
  1 0 1=(a=b+c)
  1 1 0
  1 1 2
  1 2 1
  1 2 3
  1 3 2
  1 3 4
  1 4 3
  1 4 5
  1 5 4
  1 5 6
  1 6 5
  1 6 7
  1 7 6
  1 7 8
  1 8 7
  1 8 9
  1 9 8
  2 0 2
  2 1 1
  2 1 3
  2 2 0
  2 2 4
  2 3 1
  2 3 5
  2 4 2
  2 5 3
  2 5 7
  2 6 4
  2 6 8
  2 7 5
  2 7 9
  2 8 6
  297
  303
  312
  314
  325
  321
  330
  336
  341
  347
  352
  358
  363
  374
  385
  396
  404
  ......
  
  ......
  total u got 66 no
• 8 years agoHelpfull: Yes(5) No(0)
• ans...c..
  101,112,123,134,145,156,167,178,189---9+(last 2 digit can be interchanged---so more 9 also) so total 18
  202,213,224,235,246,257,268,279----------8+(last 2 digit can be interchanged --so 8 more)+211--so total 17
  303,314,325,336,347,358,369------------7+(last 2 digit can be interchanged --so 7 more)+312,321--so total 16
  404,415,426,437,448,459-------------------------------------------------------------------------------------------------------------15
  505,516,527,538,549.............................................................................................................................................................14
  ------------------------------------------------------------------------------------------------------------------------------------------------------
  total 66
  505,516,527,538,549--------------------5
  ----------------------------------------------------33
• 7 years agoHelpfull: Yes(2) No(0)
• Answer is : c) 66
  Number between 100 to 500
  apply permutation: abo 2 ways - abo, bao ( o= zero)
  101, 202, 303, 404 => 4*2 = 8 ways
  apply permutation : aab (according to question in given range for a and b means a, b < 5)
  aab , aba, baa - 3 ways
  112, 224=> 3*2=6 ways
  if b >=5 so 336, 448 -- 2*2=4 ways
  if abc permut: 6ways
  123, 134, = 6*2 =12 ways
  if abc permute : 4 ways ( if you see c>=5)
  145, , 235, 246, 347=> 4*4= 16 ways
  if abc permuate : 2 ways( if you see b and c both >=5)
  156, 167, 178, 189, 257, 268, 279, 358, 369, 459= > 10*2= 20 ways
  so total possible number => 20+16+12+4+6+8=66 ans
  if we clearly understand it take less time with in 2 or 3 mins
• 7 years agoHelpfull: Yes(1) No(0)
• how you have counted nine no.
• 8 years agoHelpfull: Yes(0) No(1)
• 15. 6*22=132-7=125-35=90/6=15
• 8 years agoHelpfull: Yes(0) No(10)
• 2 no between 100-199 (101,110)
  3 no between 200-299 (202,220,211)
  4 no between 300-399 (303,312,321,330)
  5 no between 400-499(404,413,422,431,440)
  Total no=14
  Explanation:-
  minimum possibility of getting 1 is 0+1 and 1+0.
  minimum possibility of getting 2 is 0+2 ,2+0 and 1+1.
  minimum possibility of getting 3 is 0+3, 3+0,1+2 and 2+1.
  minimum possibility of getting 4 is 0+4, 0+4,2+2,1+3 and 3+1 .
  
• 8 years agoHelpfull: Yes(0) No(6)
• go through options one's digit 3+3=6, ten's digit =6 ans.66
• 7 years agoHelpfull: Yes(0) No(2)