Question 1013422
let assume the age of the boy be 'x' . so the age of mother would be '48-x' now according to the condition given in the question that 
48-x = 2x+3
48-3=3x
x=15
you get the value of x that is 15
now the age of boy would be 15 and age of mother would be 33
so, difference would be 33-15=  18 
18 would be your answer.