Question

Eight oranges can be bought for Rs.10.40.How many more can be bought for Rs.16.90?

Answer 1

in Rs.10.4 he bought = 8 oranges
in Rs.1 he bought = 8/10.4 oranges
in Rs.16.9 he bought = 19.9*8/10.4 = 13 oranges
so in Rs.16.9 he bought 5 more oranges.

Answer 2

8 oranges=10.40
1 orange  =10.40/8
               =1.3
oranges that can be bought for Rs. 16.90 =16.90/1.3 =13 oranges
Therefore 13 - 8 = 5 more oranges can be bought.