Question 518999
Let
Present age of Chole = x
Present age of of Brett = x/2
Present age of Adam = x/2/2 = x/4 

x+x/2+x/4=105
Multiply by LCM (4) both sides of the equation
4x+2x+x=105*4
7x=420
7x/7=420/7
x=60
Present age of Chole = x = 60 years old
Present age of of Brett = x/2 = 60/2 = 30 years old
Present age of Adam = x/2/2 = x/4 = 60/4 = 15 years old