What is the relation?

A father is 4 times his son's age. And in 30 years son's age will be half of his father's age. How old are the father and son now???

Answer: 
Son's age : 15
Father's age : 60


Explanation:
The ratio of the father and son's age is now 4 to 1 and 30 years from now it will be 2 to 1. The period of thirty years equals the difference of the two ratios or 2 to 1. Therefore, 30*2 = 60, the father's age and (1/2) * 30 = 15, the son's age.

Find out no. of days.

A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in??

Answer:

45	(or)22	1	days.
2		2

Explanation:

Ratio of times taken by A and B = 1 : 3.

The time difference is (3 - 1) 2 days while B take 3 days and A takes 1 day.

If difference of time is 2 days, B takes 3 days.

If difference of time is 60 days, B takes		3	x 60		= 90 days.
		2

So, A takes 30 days to do the work.

A's 1 day's work =	1
	30

B's 1 day's work =	1
	90

(A + B)'s 1 day's work =		1	+	1		=	4	=	2
		30		90			90		45

A and B together can do the work in	45	= 22	1	days.
	2		2