The ratio between the weight of the wheat and the cost is 5:(91.50)
When multiplying both quantity by a same number, it is an equivalent ratio.
(Also call the quantity of wheat that can be purchased as x)
5:(91.50) = x:183
(5x2):(91.50x2) = x:183
10 : 183 = x : 183
-> x = 10
So, the quantity of wheat that can be purchased in Rs. 183 is 10kg.
