IIT JEE , AIEEE Forum - Mathematics , Algebra

amulye

D SET OF D 1ST 16 NATURAL NUMBERS IS PARTITIONED INTO 4 DISJOINT SUBSETS OF 4 MEMBERS SUCH DAT D SUM OF D NO.S IN EACH SUBSET IS SAME IF A SUBSET CONTAINS 3 DEN IT ALSO CONTAINS

A) 5 B) 7 C) 9 D) 19

IF 2 EQUILATERAL TRIANGLES R INSCRIBED IN A CIRCLE OF UNIT RADIUS D MAXIMUM VALUE OF THEIR COMMON AREA IS

A) 3^1/2B) 3^1/2/2 C) 3^1/2/4 D) 6^1/2/4

D AREA OF D QUADRILATERAL ABCD IS

A) 18(2)^1/2B) 24(2)^1/2 C) 36(2)^1/2 D) 36

D COEFFICIENT OF X^r IN D EXPANSION OF

(1+3X+6X²+.............)^1/3

allamraju

For first question is option (D) 14?I got the ans as 14.

ayshwarya

no option has d 14 as answer try once again

amulye

yes i got answers fr d other also

d answers r 9, 3^1/2, 36rt2 but not getting answers fr d last question plz reply me soon

maqmip

Hey dude... for d first question all d answers r valid except d last one...

1,6,11,16 ; 2,7,10,15 ; 3,8,9,14 ; 4,5,12,13

1,8,9,16 ; 2,6,11,15 ; 3,7,10,14 ; 4,5,12,13

1,8,9,16 ; 2,7,10,15 ; 3,5,12,14 ; 4,6,11,13

All the three no.s 5.7.9 come in d set of no.3....!!!

spideyunlimited

How can it contain 19 when ur question says first 16 natural numbers?

allamraju

See..the ans must be 14.If u wish to check,see magnip's answer.All the sets which contain 3 also contain 14,but not 5,7,9 and from where did 19 come from,when there are 16 natural no.s.I think it is a printing mistake and shud be 14.

The ans can't be 9 bcoz in 3,7,10,14,there is no 9.U get more sets then what magnip mentioned,but all of them have 14 along with 3.

computer001

yep i agree id allamraju

ayshwarya

noi got d perfect answer ialso checked it iam right
i willsend u a few minutes later

ayshwarya

dsubset containing 3is{ 3,8,9,14}
or {3,6,9,16}
hence answer is 9

ayshwarya

plzsee d condition d answers given by u it is given dat sum of all nos must be same

allamraju

See ayshwarya,the sum of the terms in the set {3,7,10,14} and {3,6,9,14} are the same and the first one has no 9.Observe that both contain 14.

maqmip

As said by allamraju... 14 is always in d set of 3 but v can't neglect d presence of 5,7,9 in that set atleast for once... so d discussion doesn't end...

Ask & Discuss Questions with Community & Experts

For first question is option (D) 14?I got the ans as 14.

See..the ans must be 14.If u wish to check,see magnip's answer.All the sets which contain 3 also contain 14,but not 5,7,9 and from where did 19 come from,when there are 16 natural no.s.I think it is a printing mistake and shud be 14.

The ans can't be 9 bcoz in 3,7,10,14,there is no 9.U get more sets then what magnip mentioned,but all of them have 14 along with 3.

See ayshwarya,the sum of the terms in the set {3,7,10,14} and {3,6,9,14} are the same and the first one has no 9.Observe that both contain 14.