Answer:
Cheapest cost to pay = £906
Explanation:
Given that:
Rice to supply = 50 tonnes
Option A:
Big van has capacity of 15 tonnes.
Number of big vans =

It means that 4 big vans will be needed for transporting 50 tonnes of rice.
Cost of 4 vans = 4*250 = £1000
Option B:
Small van has capacity of 9 tonnes.
Number of small vans =

It means that 6 small vans will be nedded for transporting 50 tonnes of rice.
Cost of 6 vans = 6*151 = £906
Therefore,
The company can transport the rice through small vans.
Hence,
Cheapest cost to pay = £906