In 2000, the market shares of the toilet soaps Margo, Palmolive and dove were 40%, 30% and 30% respectively. Starting from the next year, a new soap enters into the market each year and gets 10% of the market share. The existing soap share the remaining market share in the same ratio as they did in the previous year. What percent of the total market share will mango have in 2002?

In 2000, the market share was 40%, 30% and 30%, means
the ratio is 4 : 3 : 3
In 2001, a new product (A) enters and has 10% market share, 90% of the remaining market is shared by the previous 3.
Now, divide 90% in the ratio 4 : 3 : 3 , i.e 36%, 27%, 27%.
Now the ratio is 36 : 27 : 27 : 10
In 2002, another new product (B) enters and has 10% market share, now the remaining 90% market share is distributed in the ratio,
36 : 27 : 27 : 10
and hence remaining 32.4%, 24.3%, 24.3%, 9%
Thus, the market share of Margo in 2002 is 32.4%