18) Let xyz = 150 x,y,z belong to N. Then number of ordered triplets (x,y,z) satisfying the given equation is
(A) 27
(B) 15
(C) 6
(D) None of these
Ans given A i got D
1Aveek , observe that , 6 x 5 x 5 = 2 . 3 . 5 2 only
10 . 15 . 1 = 2 . 3 . 5 2
Hence , my solution includes all cases .
1the question is as good as saying i have 4 balls. 2 of different colors, and the other 2 of the same color. i have to put them in 3 distinct boxes, empty boxes allowed.
now, say a,b,c,c a has 3 options, so does b, to arrange c, we have 3C2+3 ways. (as 2 different c's or in a group)
so total ways are 3*3*(3C2+3)
cheers!!
1Because any composite number can be written down in terms of prime numbers . Hence , the solution 6 , 5 , 10 can be thought of an imaginary solution in x = 25 , y = 2 , z = 3 .
4My doubt is same as Aveek's
Ricky plzz explain this point again
Y cant we have cases like
x= 6 y = 5 z = 5
x = 3 y = 25 z = 2
??
Y r u considering all solutions in terms of prime numbers only ?
1Ricky bhaiya !!!!!!!!!!!!!
u are distributing all possible combinations into 3 factors ..... mind it !!! (rajnikanth style) :-)
all possible combos are different.
1Yes , but I am seeing 6 x 5 x 5 as 2 . 3 . 25 , so that this ambiguity never comes only .
1@ RICKY :
distribution of 6 x 5 x 5 among three things and distribution of 1 x 10 x 15 are different cases.....
the first one includes 2 like terms and the 2nd one all 3 unlike :
4@Aveek I already posted answers for whatever qs answered
Scroll up !!!!1
4(117) An example of autocatalytic reaction is
(A) Hydrogenation of vegetable oil using Ni catalyst
(B) Thermal decomposition of KclO3 and MnO2 mixture
(c) Decomposition of nitro glycerine
4(74) The diagram below shows the change X in the length of a thin uniform wire caused by the
application of stress F at two different temperatures T1 and T2 . The variations shown
suggest that
(A) T1 > T2
(B) T1 > T2
(C) cant be said
(D) None of these
Ans B
1UTTARA ... will you only post questions or verify the answers too ??
4(94) Silver nitrate produces a black stain on skin due to
(A) Its reduction to metallic silver
(B) Corrosive action
(C) Complex formation
(D) Strong reducing action
Ans A I got C
4(75) Solids expand on heating because :
(A) The potential energy curve is asymmetric about the equillibrium distance between
neighbouring atoms
(B) Total energy of the atoms increases
(C) Kinetic energy of the atoms increases
(D) Potential energy of the atoms increases
Ans given A I got C
1@ ricky :
what bout
6 x 5 x 5.........., 10 x 3 x 5 , 2 x 15 x 5 ???? :-)
4Thanks Ricky
Ans given was 27
I was getting cases > 27
I considered x= 3 y = 50 z =1 also
Y cant we consider no.s other than primes as solutions ???
1150 = 2 . 5 2 . 3
Considering x , y , z as non - negatives ,
Each of x , y , z can assume values 2 , 5 2 and 3 in turn .
So the total number of solutions --- 3 3 = 27
