The mean of \(x\) and \(y\) is \(a\), the mean of \(y\) and \(z\) is \(b\) and the mean of \(x\) and \(z\) is \(c\). What is the mean of \(x, y\) and \(z\)?
A\(\frac{a+b+c}{3}\)
B\(\frac{a+b+c}{2}\)
C\(a+b+c\)
D\(\frac{abc}{a+b+c}\)
#82📜 ECE Board April 1998📘 1001 Math RojasEasy
Find the mean proportional of \(4\) and \(36\).
A\(72\)
B\(24\)
C\(12\)
D\(20\)
#83📜 ECE Board April 1998📘 1001 Math RojasMedium
The arithmetic mean of \(80\) numbers is \(55\). If two numbers namely \(250\) and \(850\) are removed, what is the arithmetic mean of the remaining numbers?
A\(42.31\)
B\(50\)
C\(38.62\)
D\(57.12\)
#84📜 ECE Board April 1998📘 1001 Math RojasMedium
The arithmetic mean of \(6\) numbers is \(17\). If two numbers are added to the progression, the new set of numbers will have an arithmetic mean of \(19\). What are the two numbers if their difference is \(4\)?
A\(21, 25\)
B\(23, 27\)
C\(8, 12\)
D\(16, 20\)
#85📜 ECE Board March 1996📘 1001 Math RojasMedium
The equation of whose roots are the reciprocal of the roots of \(2x^2-3x-5=0\) is,
A\(5x^2+3x-2=0\)
B\(2x^2+3x-5=0\)
C\(3x^2-3x+2=0\)
D\(2x^2+5x-3=0\)
#86📜 EE Board October 1993📘 1001 Math RojasEasy
In the equation \(x^2+x=0\) one root is \(x\) equal to
A1
B5
C\(1/4\)
Dnone of these
#87📜 ECE Board April 1990📘 1001 Math RojasMedium
Solve for the value of "a" in the equation \(a^8-17a^4+16=0\)
A\(\pm 2\)
B\(\pm 3\)
C\(\pm 4\)
D\(\pm 5\)
#88📜 ME Board October 1996📘 1001 Math RojasEasy
Solve for \(x\) that satisfies the equation \(6x^2-7x-5=0\).
A\(\frac{5}{3}\) or \(\frac{-1}{2}\)
B\(\frac{3}{2}\) or \(\frac{3}{8}\)
C\(\frac{7}{5}\) or \(\frac{-7}{15}\)
D\(\frac{3}{5}\) or \(\frac{3}{4}\)
#89📜 EE Board October 1997📘 1001 Math RojasEasy
Find the values of \(x\) in the equation \(24x^2+5x-1=0\)
A\((\frac{1}{6}, 1)\)
B\((\frac{1}{6}, \frac{1}{5})\)
C\((\frac{1}{2}, \frac{1}{5})\)
D\((\frac{1}{8}, -\frac{1}{3})\)
#90📜 EE Board October 1990📘 1001 Math RojasEasy
Determine \(k\) so that the equation \(4x^2+kx+1=0\) will have just one real solution.
A3
B4
C5
D6
#91📜 ME Board April 1996📘 1001 Math RojasEasy
Solve for \(x\): \(10x^2+10x+1=0\)
A\(-0.113, -0.887\)
B\(-0.331, -0.788\)
C\(-0.113, -0.788\)
D\(-0.311, -0.887\)
#92📘 1001 Math RojasMedium
If \(1/3\) and \(-3/2\) are the roots of a quadratic equation, then the equation is
A\(6x^2+7x-3=0\)
B\(6x^2-7x+3=0\)
C\(6x^2-7x-3=0\)
D\(6x^2-7x+1=0\)
#93📘 1001 Math RojasEasy
Which of the following is a root of this quadratic equation, \(30x^2+49x+20=0\)?
A0.6
B-0.6
C-0.8
D0.75
#94📘 1001 Math RojasEasy
What is the discriminant of the equation \(4x^2=8x-5\)?
A8
B-16
C16
D-8
#95📘 1001 Math RojasEasy
Given the equation \(3x^2+Bx+12=0\). What is the value of \(B\) so that the roots of the equation are equal?
A4
B8
C10
D-12
#96📘 1001 Math RojasMedium
Find the term involving \(y^5\) in the expansion of \((2x^2+y)^{10}\)
A\(8064 x^{10}y^5\)
B\(8046 x^5y^5\)
C\(8046 x^{10}y^5\)
D\(4680 x^5y^5\)
#97📘 1001 Math RojasMedium
Find the \(5^{th}\) term of the expansion of \((x^2+\frac{1}{x})^{10}\)
A\(260 x^8\)
B\(5040 x^8\)
C\(210 x^8\)
D\(420 x^8\)
#98📜 ECE Board April 1998📘 1001 Math RojasMedium
In the expression of \((x+4y)^{12}\), the numerical coefficient of the \(5^{th}\) term is,
A63,360
B126,720
C506,880
D253,440
#99📘 1001 Math RojasMedium
What is the fourth term of the expansion of \((x+x^2)^{100}\)?
A\(1650 x^{103}\)
B\(161700 x^{103}\)
C\(167100 x^{16}\)
D\(167100 x^{100}\)
#100📘 1001 Math RojasMedium
What is the numerical coefficient of the term next to \(495x^8y^4\)?