3 .The height of a triangle is increased by 10%. To retain the original area of the triangle, its corresponding base must be decreased by ?
A. 9$1\over8$%
B. 9$1\over7$%
C. 9$1\over11$%
D. 10%
5 .A man bought a watch at 25% discount on the original price. He got ` 40 more than the original price by selling it at 140% of the price at which he bought. The price of buying the watch was ?