How old are the father and son at present if a father's age is five times his son's age and four years ago the father was 9 times older than his son?

40yrs and 8yrs

You can solve this by rough estimation given you have multiple choice here. You can quickly see that each of the first 3 answers satisfy the condition that the father is currently 5 times the age of the son. By subtracting 4 years from each age in each answer you will see them as follows: a: 26 and 2 b: 21 and 1 c: 36 and 4 Now it is clear that the answer is c: 40 and 8 (because 4 x 9 = 36 and 5 x 8 = 40). These questions are why it is important to learn your multiplication tables prior to testing.