Math help please

Question

Three friends have a total of 100. Mike has 4 times what Dave has and Linda has 10 less than Dave. What does each friend have?

Please show work as I got this question wrong on an exam and i would like to know how to work it out.

Answer 1

Hi, Becca! (Love your name!)

 

Ok, So let's say Dave has X amount. I used X for Dave because his friends' amounts are given in terms of how much he has.

 

X = Dave

4X = Mike

X - 10 = Linda

 

Now, we just add them up 

X + 4X + (X - 10) = 100

6X -10 = 100

6X = 110

Dave = X = 18 1/3

Mike = 4X  = 73 1/3

Linda = X-10 = 8 1/3