A man sells two tables at the same price. On one he makes a profit of 10% and on the other he suffers a loss of 10%. His loss per cent on the whole transaction is

1)0

2)1

3) 2

4) 5

 If 18, persons can build a 140m long wall in 42 days, the number of days that 30 persons will take to complete a similar 100m long wall is :

(1) 18

(2) 21

(3) 24

(4) 28