# Recent questions and answers in K-12

Which city has the median population value?
City Population in Millions Melbourne 3.2 Bangkok 7.2 Nairobi Paris 9.6 São Paulo 17.7 Tokyo 28.0 Seattle 2.1
For each positive integer n , defind H(n) as the following. Prove that if n>=2, then H(n) is not an integer

$H(n)=1+ \frac{1}{2}+\frac{1}{3}+ ...+\frac{1}{n}$

What is c if b and c are constants and

$(x+2)(x+b) = x^2 + cx + 6$

Find the value of abc if a+b+c=0 and

$a^3+b^3+c^3 =216$

What is the greatest common factor of 42, 126, and 210 ?

What is the greatest common factor of 42, 126, and 210 ?

How many irrational numbers are there between 1 and 6 ?

How many irrational numbers are there between 1 and 6 ?

what is 50% of 60% of 180??
what is 50% of 60% of 180??
if average of 3y, 4y and (y-5) is 9, what is the value of y??
if average of 3y, 4y and (y-5) is 9, what is the value of y??
What is the value of x when 2x + 3 = 3x – 4 ?

What is the value of x when 2x + 3 = 3x – 4 ?

Sales for a business were 3 million dollars more the second year than the first, and sales for the third year were double the sales for the second year.

Sales for a business were 3 million dollars more the second year than the first, and sales for the third year were double the sales for the second year. If sales for the third year were 38 million dollars, what were sales, in millions of dollars, for the first year?

A car averages 27 miles per gallon. If gas costs $4.04 per gallon, which of the following is closest to how much the gas would cost for this car to travel 2,727 typical miles? A car averages 27 miles per gallon. If gas costs$4.04 per gallon, which of the following is closest to how much the gas would cost for this car to travel 2,727 typical miles?

if a circle with center (3,4) is tangent to x-pixie, what is the circumference of this circle??
if average of 3y, 4y and (y-5) is 9, what is the value of y??
Let a, b, c be the roots of the

$x^3-2x^2+x+5=0$

Find the value of

$a^4+b^4+c^4$

$x^4-x^3-7x^2+23x-20=0$
$(a/b)+(b/c)+(c/a) \geq a + b+c$