Explain with step by step instructions in advance

36.4%

Step-by-step explanation:

You know the most about Kim and Molly, so you should start with them.

Let kim's share = x

Therefore Molly's share = x + 105

Ratio

Kim is to Molly as 2 is 5

2/5 = x / (x + 105)              

Solution

Cross multiply

2(x + 105) = 5x             Remove the brackets.

2x + 2*105 = 5x           Consolidate.

2x + 210 = 5x                Subtract 2x from both sides

2x - 2x + 210 = 5x - 2x Reduce like terms.

210 = 3x                         Divide by 3

210/3 = x

70 = x                        

Laura's Share.

Kim = x = 70

Molly = x + 105 = 70 + 105 = 175

Kim + Molly + Laura = 385

70 + 175 + Laura = 385      Combine the  left side

245 + Laura = 385             Subtract 245 from both sides

Laura = 385 - 245              Combine the right. (Subtract)

Laura = 140

Laura's %

Laura's % = (140 / 385) * 100 = 36.4 to 3 places.