so this can be solve by establish two equation:
let x be age of montell
y be tha age of her mom
for the first equation (Montell is 30 years):
x = y - 30
second equation ( in 5 years )
x + 5 = ( y + 5 ) ( 1/3)
solving the equation simultaneously
x = 10 years old
y = 40 years old
