396]
solve one by one. not randomly... please.
1]the total 8 digit numbers of the form x_{1}x_{2}x_{3}x_{4}x_{5}x_{6}x_{7}x_{8} such that x5 is the greatest digit and digits towards the left and right of x5 are in decreasing order are (repetition allowed)
a]11575
b]12500
c]12595
d]none of these
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21 Answers
1for 8] its(c)..........
THE CURRENT GETS CONFINED TO D LOOP ABCD..
H=VIt.......
HERE V=V1.
SO IT DEPENDS ON V1 rit???????
39great answer............................
there is nothing to explain. just that clemmenson is used for base sensitive gruops but not acid sensitive. here oh is acid sensitive , so will go with h of hcl. and cl will attach in placce of oh.
1yeh wala B hoga... HCl eracts with OH... and it reaplces OH by Cl.
long ago i had explained this one somewhere in the organic section...
dats y in places where OH is theer... wolf-kishner is preferred over clemmenson..
15.) wenever u will close one of the switches or both... the PD will become same for the joined section so at that portion there will be no current ...
like wen u close switch S1, there will b no current through 2 Ω [this is the first time i used this symbol [5]] batery.
11this one looks similar to
http://targetiit.com/iit_jee_forum/posts/p_c_an_interesting_one_4184.html
1hey b555, pls upload that second paper .. physics.. partA(3marks wala) .. circuit problem.... that one with switches V1 and V2..
plz...... i dun have scanner :'( ... plz do...
1fifth digit is d greatest and digits to d left n right of it decreases... implies fifth digit can be either 5,6,7,8 or 9... (since first four digits at d least can b 1,2,3,4)
if x5=5, v have four digits available for d left side of it viz., 1,2,3,4 and 5 digits for d right side of it., 0,1,2,3,4... for left side of x5, four digits are to be selected and there exists only one order in which they can be arranged in decreasing order... and for d right side of x5, 3 digits are to be selected from all possible digits and there exists only one decreasing order... implies... total no. of 8 digit no.s possible wid given conditions when x5=5 are 4C4.5C3
similarly when
x5=6, n(E) = 5C4.6C3
x5=7, n(E) = 6C4.7C3
x5=8, n(E) = 7C4.8C3
x5=9, n(E) = 8C4.9C3
d sum comes out to be 8475... hence ans. is "none of these"
a slightly extended form of this question is here...
http://targetiit.com/iit_jee_forum/posts/p_c_an_interesting_one_4184.html
hope it helps... [1]
392] if the equation x^{4}+ax^{3}-x^{2}+4ax+16=0 has atleast 2 distinct positive real roots, then a \epsilon
a](-∞ ,-7/4)
b](-∞,7/4)
c](-∞,-2)
d) (-∞,-7/4) U (7/4 , ∞)