Top answers

There are 20 balls in a bag. The probability is 0.25 of picking a red ball. If one more red ball is added, what is the new probability of picking a red ball at random?

Convert 0.25 into a fraction where 20 is the denominator as there are 20 balls in total in the bag. 0.25 is the same as 1/4 and to convert this to 20 as the denominator multiply both the top and the bottom b...
AL
Answered by Alex L. • Maths tutor
12439 Views

The area of a square is 49cm^2. The perimeter of the square is equal to the circumference of a circle. what is the radius of the circle?

This is a geometry question. We know that a square has 4 equal sides of x, and that it's area is given by A=x 2 . So we can work out the length of the side of the square. x=sqrt(49) = 7 We are told this is e...
JC
Answered by Julia C. • Maths tutor
16371 Views

Solve these simultaneous equations: y=3x-10; y=2x+5

Method 1 (algebraically): Since we have "y=" at the start of both equations, we can substitue one into the other to get 3x-10=2x+5 Then we want all the x terms on one side of the equation, and all ...
CW
Answered by Catherine W. • Maths tutor
11230 Views

Solve the simultaneous equation: 3x+y=-2, -7x+5y=34.

3x+y=-2 ...1) -7x+5y=34 ...2) Using the substitution method: Rearrange equation 1): y=-3x-2 ...1)) substitute equation 1)) into eqaution 2) -7x +5(-3x-2)=34 -7x-15x-10=34 -22x=44 x=-2 subsitute x into 1)) y=...
SJ
Answered by Shaan J. • Maths tutor
9095 Views

If f(x) = 4x - 7 and f(c) = 9, find the value of c.

To find the value of c, we need to find the value of x in the following: 4x - 7 = 9. Add seven to both sides: 4x = 16 Divide by 4: x = 4
AB
Answered by Andrew B. • Maths tutor
6805 Views