# Recently Active Algebra Questions

• The value of the expression 47C4 + j=15Σ52-j C3 IS ... ...
replied2014-02-09 19:03:50
• Find the H.C.F. of the minimum non-negative values of a,b and c, given that the equation x4+ax3+bx2+cx+1=0 has only real; roots ... ...
• For positive integers n1 and n2 , the value of the expression (1+i)n1+(i+13)n1+(i+15)n2+(i+17)n2 here i= -1 is real if and only if (A)n1=n2+1 (B) n1=n2-1 (C) n1=n2 (D)n1>0,n2 >0 pl post the soln as well . ...
replied2014-02-06 20:52:44
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replied2014-02-06 13:47:04
• *Image* a)For the first part the expected value would be = E(x)=\frac{1}{2}+2\left(\frac{1}{2}\right)^2+3\left(\frac{1}{2}\right)^3+\cdots=2 b)For the second part the expected value would be = E(x)=\frac{1}{2}+\frac{2}{4}+\fr ...
replied2014-01-31 06:33:41
• The solution set of frac{{{x^2} - 3x + 4}}{{x + 1}} > 1,,x in R , is a) (3,,, + infty ) b) ( - 1,,,1) cup (3,,, + infty ) c) [ - 1,,,1] cup [3,,, + infty ) d) None of these ...
• 3.nc0-8.nC1+13.nC2-18.nC3.......... upto (n+1) terms =? ...
replied2014-01-04 01:06:44
• Find the coefficient of xr in the following- (x+2)n+(x+2)n-1(x+1)+(x+2)n-2(x+2)2+.....+(x+1)n ...
replied2014-01-04 00:44:47
• The probability that a randomly chosen relation from a set A = {1, 2, . . . n}, n ≥ 1 to itself is a symmetric relation is (A) 2- n2+n/2 (B) 2 -n2/2 (C) 2 n-n2/2 (D) 2 n+1-n2/2 ...
• The value of i log(x – i) + i2+i3 log(x +i) + i4( 2 tan-1x), x> 0 is (A) 0 (B) 1 (C) 2 (D) 3 ...
replied2013-12-26 09:33:04
• The product of n positive numbers is unity.Then their sum is a.a positive integer b.divisible by n c.equal to n + 1/n d.never less than n Let the numbers be a1,a2,a3.......an Applying A.M>=G.M we get, a1+a2+a3+............ ...
replied2013-12-26 04:19:36
• Consider a 25*25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up ...
replied2013-12-23 00:58:38
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replied2013-12-17 22:42:55
• in how many ways we can make a 4 digit no. using 1,2,3,4 and what's the sum of all the numbers obtained?(repeatations not allowed) ...
replied2013-12-17 22:34:58
• If a,b,c be the pth,qth and rth terms of an HP respectively then prove the system of equations- (bc)x + (ca)y + (ab)z = 0 px +qy + rz =0 and x+y+z=0 has ∞ number of solutions ...
replied2013-12-12 23:38:13
• If a,b,c are in AP ;b,c,a In GP then prove that 1/c , 1/a , 1/b are in ap ...
replied2013-12-08 21:00:24
• This is a great problem which you can probably approach in a number of different ways. All natural numbers are arranged as follows. 1 3 6 10 15 . 2 5 9 14 . . 4 8 13 . . . 7 12 . . . . 11 . . . . . and so on. Find the row and ...
• Three distinct numbers are selected uniformly at random from the ten-term geometric sequence with first term 10/9 and common ratio 2 . What is the expected value of their sum? ...
replied2013-11-29 07:02:49
• Find till infinity: 1 - n^2 + {n^2(n^2-1^2)}/(2!)^2 - {n^2(n^2-1^2)(n^2-2^2)}/(3!)^2................................ to infinity,where n belongs to N. ...
replied2013-11-08 04:41:07
• If each pair of the following three equations x2+ax+b=0, x2+cx+d=0, x2+ex+f=0 has exactly one root in common,then show that (a+c+e)2=4(ac+ce+ea-b-d-f). ...
replied2013-10-29 19:01:29
• A box contains coupons labeled 1,2,3,....n. A coupon is picked at random and the number x is noted. The coupon is put back into the box and a new coupon is picked at random. The new number is y. Then the probability that one ...
replied2013-10-28 20:32:30
• Let S={1,2,3,...,n} and A={(a,b)l1≤a,b≤n}=S X S. A subset B of A is said to be a good subset if (x,x) belongs to B for every x belonging to S. Then the number of good subsets of A is A. 1 B. 2n C.2n(n-1) D.2n2 The answer ...
replied2013-10-24 00:54:06
• \hspace{-16}$Find all real polynomials$\bf{p(x)}$such that$\bf{p(x)\cdot p(x+1)=p(x^2)\;\forall x\in \mathbb{Z}}$... asked2013-10-18 21:12:22 • The maximum value M of 3x+5x-9x+15x-25x,as x varies over reals,satisfies A.3<M<5 B.9<M<25 C.0<M<2 D.5<M<9 ... replied2013-10-18 21:05:20 • \hspace{-16}$In how many ways can the selection of $\bf{8}$ letters be done frm $\bf{24}$ letters\\\\ of which $\bf{8}$ are $\bf{'a'}$ and $\bf{8}$ are $\bf{'b'}$ and rest are unlike. ...
replied2013-10-17 22:26:29
• Three children,each accompanied by a guardian,seek admission in a school.The principal wants to interview all the 6 persons one after the other,subject to the condition that no child is interviewed before its guardian.In how ...
replied2013-10-17 00:15:39
• If 'a' is a complex number such that |a|=1.Find the values of a,so that equation az2+z+1=0 has one purely imaginary root. ...
replied2013-10-13 23:02:29
• S=1-1+1-1+1-1....................... infinity now thus, S=1- (1-1+1-1+1-1....................... infinity) thus S=1-S thus 2S=1 S=1/2 ...
replied2013-10-11 21:56:12
• (555)37 ...
replied2013-10-09 19:21:19
• There are 5 different red balls,5 different green balls,5 different blue balls and 5 different black balls.In how many ways can they be arranged so that no two balls of same color are adjacent ? ...