Question 813173
father = x
Bob = y
Son = z
x = 25 + y
y = y
z =y - 27
x + y + z = 100
{{{(25+y) + y + (y-27) = 100}}}
{{{25 + y + y + y - 27 =100}}}
{{{3y - 2 = 100}}}
{{{3y = 102}}}
{{{y = 34}}}
Bob is 34. since his father is 25 years older, his father is 59. Since his son is 27 years younger, his son is 7.
34 + 59 + 7 = 100