Top answers

In a bag of balls, 3 are red, 2 are blue and 5 are green. Two balls are selected from the bag. Calculate the probability that both are green.

Answer:2/9On the first pick of the bag, there are 10 balls in total. Out of these balls, 5 are green. Therefore the probability of picking a green ball will be 5/10 or 1/2. On the second pick of the bag, the...
CH
Answered by Charlie H. • Maths tutor
11280 Views

A right angled triangle has two short sides of lengths 5cm and 12cm respectively. What is the length of the third side?

13cm. Using Pythagoras theorem a^2 +b^2 =c^2 we substitute our two known lengths into the equation to get 5^2 + 12^2=c^2. So now we have c^2= 25+144. So c^2 =169. So c=√169 = 13. Don't forget the units!!! So...
NC
Answered by Niall C. • Maths tutor
9080 Views

How can I maximise my performance and efficiency in an exam?

Confidence in your mathematical ability and subsequent answers in an exam is key. During an exam you should be confident with the answers that you are giving which can be achieved with steady revision and at...
JS
Answered by James S. • Maths tutor
3830 Views

The two points (4,9) and (2,3) are on line A. A second line, line B is perpendicular to line A and goes through the point (2,3). What is the equation of line B?

Step 1, find the gradient of line A: gradient = change in y/change in x = (y1 - y2) / (x1 - x2) = 9-3/4-2 = 6/2 = 3Step 2, find the gradient of line B: as the two lines are perpendicular, the gradient of lin...
GW
Answered by Georgia W. • Maths tutor
3317 Views

What is a derivative and how are they used?

A derivative is a function that tells us the gradient of a curve at any point. Say you have a function like f(x)=x 3 +x 2 and you want to know when the function is stationary, i.e. has a gradient of zero. We...
NS
Answered by Nikhil S. • Maths tutor
4217 Views