Question 831635
Let your age be x, so you have your sister's age is x+8, and your mother age is x+8+25 which means x + 33 
Product means you have to multiply them, so you have 
{{{x*(x+8)*(x+33)}}} = {{{18816}}}
{{{(x^2+8x)*(x+33)}}} = {{{18816}}}
{{{x^3 + 41x^2 + 264x - 18816}}} = {{{(0)}}}
Now you solve the equation, which will takes you almost a paper, or you can use a scientific calculator and solve it in 10 seconds, you will have 3 answers of x, but only one of them is a whole number
x = 16 
Your mother age is x+33 right? 
TA-DAH
Your mother age is 16+33 = 49 years old :D