33.33% of P's income is equal to 66.66% of Q's income, and 25% of Q's income is equal to 70% of R's income. They invested for 2 years, 3 years and 4 years respectively. Find the ratio of their profit at the end.

28 : 21 : 10

⇒ 33.33% P = 66.66% Q

⇒ P = 2 Q

⇒ P : Q = 2 : 1

Similarly

⇒ 25 % Q = 70% R

⇒ 5Q = 14R

⇒ Q : R = 14 : 5

Now,

⇒           P     :       Q      :        R

              2    :       1

                           14     :         5   

Inv.  :    28   :      14    :        5

Time:      2    :       3      :        4

          ---------------------------------

Profit:   56   :      42     :     20

             28  :      21      :      10 

*(Profit ratio = Inv. ratio × time ratio)