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 9,18,21,25,20,? (IBM Question) Asked by SaikatCompile Program
 Aparajita   @ Arup chowdhury how? 7 years ago
 Shobhit Saxena   @tapas how? 7 years ago
 Saptarshi Ghosh   tell me the logic? 7 years ago
 shubhi agrawal   its 27, 9+18=27,2+7=9 21+25=46,4+6=10 20+27=47,4+7=11 so it should be 27... 7 years ago
 thamaraikannan   i think 21 9+(3*3)=18 21+(2*2)=25 20+(1*1)=21 7 years ago
 thamaraikannan   it would be easy if choices are given 7 years ago
 Vivek   15 7 years ago
 Atul Gupta    10 or 9 20-18=2 25-21=4 hence x-9=1 or x-9=0 x=10 or 9 7 years ago
 soujanya   @Vivek how 15???? tell me your logic 6 years ago
 Bhumika   ANSWER WILL BE 36 6 years ago
 Bhumika   9*2-0=18 9*3-6=21 9*4-11=25 9*5-15=20 9*6-18=36 6 years ago
 Jeet Roy   @Bhumika how can 9*5-15 be 20 ? 6 years ago
 Lucy Desouza   I think Answer will be 19 Logic: 9,18,21,25,20,?((19)) Ist Difference : 9 ,3,4, -5 ((( -1))) 2nd Difference: -6,1,-9 (((4))) 3rd Difference:7 , -10 ((((13))))--Below for details Right of -10 the Number will be positive greater than 10 so think it as 13 because Its increased by magnitude three. 7,-10,13.Now move up the order to get 19 6 years ago
 Anand Kumar   40 6 years ago
 chirag    I thing answer will be 55 Explanation: 9, 18, 21, 25, 20, ? 1, 2, 3, 4, 5, 6 ---------->position no On the basis of combination of their position Taking (1,3)=1st combination (2,5)= 2nd combination (4,6)= 3rd combination in 1st : 9=3*3 21=3*7 In 2nd: 18=2*9 20=2*10 In 3rd: 25=5*5 x= 5*y 3rd combination are following the pattern same as 1st combination Prime no1*prime no1 Prime no1*prime no 2 If we following this pattern y will be 11(in 1st patter equation taking 7 as prime no2 not to 5, so i m taking 11 as another prime no) 5*5=25 5*11=55 6 years ago
 kamlesh meher   9*2-0=18 9*3-6=21 9*4-11=25 9*5-15=20 9*6-18=36 6 years ago
 Amit Kumar   9*5-15=30 not 20 wrong logic 6 years ago
 shubhra gupta   i think it is a wrong question... 6 years ago
 Amarjeet Kumar   for this type of series.. we will divide series in two part.. 9,18, 21 and 25,20,---. 3*3=9 (3*1=3) 3*6=18 (3*2=6) 3*7=21 (3*2+1=7) next...just reverse order.. 5*5=25 (2*2+1=5) 5*4=20 (2*2=4) 5*2=10 (2*1=2) so Ans is "10" 6 years ago
 santosh kumar sahu   yes u are ri8tttt 6 years ago
 bikesh   16 5 years ago
 s janani   answer is 21 take the numbers in positions 1,3 and 5 9+3^2=18 21+2^2=25 20+1^2=21 5 years ago
 ABHAY   10 4 years ago