Question

Frank has twice as many CDs as Vanessa. Lois has 4 less than 2 times as many CDs as Frank. If there is a total of 115 CDs for all 3 people, how many CDs does each person have?

Answer 1

So Frank has 34 CDs, Vanessa has 17 CD's and Lois has 64 CDs

Explanation:

Let's call the amount of CDs that Frank has by 'F', that Vanessa has by 'V' and that Lois has by 'L'. Then, we can write the following equations:

F = 2*V

L = 2*F - 4

F + V + L = 115

If we use the values of F and L in the third equation, we have that:

2*V + V + 2*(2*V) - 4 = 115

7*V = 119

V = 17 CD's

Now we can find F:

F = 2*V = 34 CDs

And then we find L:

L = 2*F - 4 = 68 - 4 = 64 CDs

So Frank has 34 CDs, Vanessa has 17 CD's and Lois has 64 CDs

Answer 2

Frank, Vanessa, Lois have 34, 17, 64 disks respectively

Explanation:

In this question, we are to calculate the number of disks each of the 3 has.

Let the number of disks owned by Frank be x

for vanessa, she has half of what frank has and that would be x/2

Lois has 4 less than 2 times what Frank has, that would be 2x - 4

adding the 3, we have a total of 115 disks

This means that;

x + x/2 + (2x-4) = 115

Multiply throughout by 2;

that gives;

2x + x + 4x - 8 = 230

7x -8 = 230

7x = 230+ 8

7x = 238

x = 238/7

x = 34 disks

Frank has 34

Vaness has 34/2 = 17

Lois have 2x - 4 = 2(34) - 4 = 68 - 4 = 64 disks