@Subhashdec2 said:w=x^24
@albiesriram said:
@Narci said:60
OA is 60 .
@albiesriram said:
y^2=4(y+15)
y^2-4y-60=0
y=4+- sqrt(16+240)/2
y=10 or -6
case 1
x^2+18x+30=10
x^2+18x+20=0
Product= 20
case 2
x^2+18x+30=-6
x^2+18x+36 = 0
product=36
36*20=720
y^2-4y-60=0
y=4+- sqrt(16+240)/2
y=10 or -6
case 1
x^2+18x+30=10
x^2+18x+20=0
Product= 20
case 2
x^2+18x+30=-6
x^2+18x+36 = 0
product=36
36*20=720
@dushyantagarwal said:If you post solution to this .. please tag me. I didn't even get the idea how to attempt these type of questions.
Probability wala sum..
atleast 2 same => 2 same + 3 same + all same or 1 - prob( all different)
hence, prob of all 4 being different = 6C4/6^4
Hence 1 - 6C4/6^4 = 1281/1296 = 427/432 = 859
Correct me or tag me with OA..! @Logrhythm @jain4444
atleast 2 same => 2 same + 3 same + all same or 1 - prob( all different)
hence, prob of all 4 being different = 6C4/6^4
Hence 1 - 6C4/6^4 = 1281/1296 = 427/432 = 859
Correct me or tag me with OA..! @Logrhythm @jain4444
OA is 20 only.
regards goes to
scrabbler 
@sbharadwaj said:Probability wala sum..atleast 2 same => 2 same + 3 same + all same or 1 - prob( all different)hence, prob of all 4 being different = 6C4/6^4Hence 1 - 6C4/6^4 = 1281/1296 = 427/432 = 859Correct me or tag me with OA..! @Logrhythm@jain4444
Not 6C4, I think should be 6P4....as in the denominator you are considering the order...
so (6 x 5 x 4 x 3) / (6 x 6 x 6 x 6) = 5/18.
So 1 - 5/18 = 13/18 => 13 + 18 = 31?
regards
scrabbler
so (6 x 5 x 4 x 3) / (6 x 6 x 6 x 6) = 5/18.
So 1 - 5/18 = 13/18 => 13 + 18 = 31?
regards
scrabbler
@albiesriram said:OA is 20 . I think they havent considered the roots when y=-6 y =_/ 4(y+15) and they have considered the positive root only. according to them oa is 20.anyway screw them 720 is neat
@albiesriram said:
6^83+8^83 mod 49
E(49) = 42
6^84 mod 49=1
6^83*6 mod 49=1
6R+1=49k
R=8
8^84 mod 49=1
8^83*8 mod 49=1
8R+1=49k
R=6
8+6=14??
@scrabbler said:What is the y in this? I didn't get it...@Subhashdec2 regardsscrabbler
see the ques in post #26035
x^2+18x+30 has been taken as y
@Subhashdec2 said:see the ques in post #26035x^2+18x+30 has been taken as y
Ah that's what I thought - was just confirming in case I was seeing the wrong problem! Then you should not take the second case...
See the original problem states:
If you are taking x^2+18x+30=-6 then you are saying that 2sqrt(x^2 +18x+45) = -6 or sqrt(x^2 +18x+45) = -3....but the sqrt function is BY DEFINITION positive only so we could only take a positive value for it....so only the 20 waala case should be considered.
regards
scrabbler
See the original problem states:
If you are taking x^2+18x+30=-6 then you are saying that 2sqrt(x^2 +18x+45) = -6 or sqrt(x^2 +18x+45) = -3....but the sqrt function is BY DEFINITION positive only so we could only take a positive value for it....so only the 20 waala case should be considered.
regards
scrabbler
@scrabbler said:Not 6C4, I think should be 6P4....as in the denominator you are considering the order...so (6 x 5 x 4 x 3) / (6 x 6 x 6 x 6) = 5/18.So 1 - 5/18 = 13/18 => 13 + 18 = 31?regardsscrabbler
shouldn't we do it like this
when 2 are same -> 6*5*4
when 3 are same -> 6*5
when all same -> 6
when 2 same and other 2 same -> 6*5
total = 186
prob = 186/6^4 = 31/216
=> 216+31 = 247
kya galti kar raha hun mein?? 
@albiesriram said:
35?
(7-1)^83 + (7+1)^83, expand and ignore powers of 7 higher than 1, we get 2*(84-1)*7= -14 =35
@scrabbler said:Ah that's what I thought - was just confirming in case I was seeing the wrong problem! Then you should not take the second case...See the original problem states:If you are taking x^2+18x+30=-6 then you are saying that 2sqrt(x^2 +18x+45) = -6 or sqrt(x^2 +18x+45) = -3....but the sqrt function is BY DEFINITION positive only so we could only take a positive value for it....so only the 20 waala case should be considered.regardsscrabbler
yea ryt
i looked the other way round
sqrt(y+15)=
y=-6
sqrt(9)
and indeed i was wrong...:D
@Logrhythm said:shouldn't we do it like thiswhen 2 are same -> 6*6*6 when 3 are same -> 6*6when all same -> 6when 2 same and other 2 same -> 6*5total = 288prob = 288/6^4 = 2/9=> 2+9 = 11 kya galti kar raha hun mein??
Can you explain these two lines (in bold)? Not getting what you did there. Also, have reservations about the 6*5 in the 4th line but will address that later once I get the thought process.
regards
scrabbler
regards
scrabbler
@Logrhythm said:shouldn't we do it like thiswhen 2 are same -> 6*5*4 when 3 are same -> 6*5when all same -> 6when 2 same and other 2 same -> 6*5total = 186prob = 186/6^4 = 31/216=> 216+31 = 247kya galti kar raha hun mein??
@scrabbler said:Can you explain these two lines (in bold)? Not getting what you did there. Also, have reservations about the 6*5 in the 4th line but will address that later once I get the thought process.regardsscrabbler
had edited my post
thought process: let ABCD be the four numbers chosen
case 1) let A and B be the same, ways to selecting A/B = 6
ways of selecting C = 5
ways of selecting D = 4
case 2) A,B and C are same, ways of selecting A/B/C = 6
ways of selecting D = 5
case 3) all A,B,C and D are same, way of selecting any = 6
case 4) A and B are same and C and D are same, ways of selecting A/B = 6
ways of selecting C/D = 5
abb batao kahan pe galti kar raha hun??
@RDN said:35?(7-1)^83 + (7+1)^83, expand and ignore powers of 7 higher than 1, we get 2*(84-1)*7= -14 =35
OA 