20% of the children in a sports club play tennis.

25% of the children who play tennis also play rounders.

There are 8 children in the club who play both tennis and rounders.
How many children are there in the sports club altogether?

160 children

Step-by-step explanation:

We can get this solution by working backwards in the equation.

First, we can treat the total number of students who play tennis as 't'. Giving us the equation: 8 = .25(t) . Solving this we get that there are 32 tennis players.

Next, we have to derive the total number of children in the sports club. Setting up 'x' as the total number of children, I get the equation 32 = .2(x) . Which leads us to the solution of 160 children in the sports club.

Step-by-step explanation:

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204