All Questions
Huỳnh Anh Phương
04/10/2018 at 05:32
It's easy!
The sum of the deominator and the numerator is constantly 1807.
So, \(?\) is \(\dfrac{15}{1792}\).
Huỳnh Anh Phương selected this answer.
Linh Đậu Nguyễn Huyền
03/10/2018 at 14:26
We have:
\(a^2+b^2+c^2\ge ab+bc+ca\)
The "=" happen when and only when a = b = c
Applying the CauchySchwarz inequality, we have:
\(\dfrac{1}{a^2+2}+\dfrac{1}{b^2+2}+\dfrac{1}{c^2+2}\le\dfrac{\left(1+1+1\right)^2}{a^2+b^2+c^2+2+2+2}\le\dfrac{9}{ab+bc+ca+6}=\dfrac{9}{9}=1\)
So......................
Selected by MathYouLike
Huỳnh Anh Phương
02/10/2018 at 10:21
? is \(\dfrac{386}{862}\).
Huỳnh Anh Phương selected this answer.
Ngdduong1412
30/09/2018 at 13:51
Huy Toàn 8A (TL) 02/10/2018 at 06:00
In 6 days, every day do 8h need the number of people is :
6 . 9 : 6 = 9 (people
In 6 days, every day do 9h need the number of people is:
9 . 8 : 9 = 8 (people)
The answer is : 8 people
Selected by MathYouLike
Huỳnh Anh Phương
30/09/2018 at 11:13
There are: 3*8*4=96 combinations that Billy can make. Huỳnh Anh Phương selected this answer.

There are: \(3\times2\times5=30\)combinations
Selected by MathYouLike
Quoc Tran Anh Le Coodinator
14/09/2018 at 07:084694
questionsWeekly ranking
Tags
games 18
double counting 8
generating functions 2
probabilistic method 1
Polynomial 8
inequality 11
area 16
Equation 8
Primitive Roots Modulo Primes 1
Primitive in Arithmetic Progression 6
Base n Representatioons 4
Pell Equation 1
mixed number 1
Fraction 29
Circle 3
Imaginary numbers 1
Decimal number 2
Volume 2
percentages 6
simple equation 19
absolute value 19
rational numbers 20
Operation of Indices 21
Simulataneous Equation A System of Equations 25
Multiplication of Polynomial 17
divisibility 24
Maximum 5
Minimum 6
Fraction 4
Prime Numbers and Composite Numbers 13
Square Number 26
Even and Odd Numbers 13
GDC and LCM 11
GCD and LCM 12
Permutation and combination 9
combinations 5
interger 7
number 10
Diophantine equations 2
equations 1
Grade 6 19
Power 3
equality 2
maximaminima 2
square root 1
Polygon 2
IGCSE 1
factorial 1
integers 1