The following table shows the production of food grains in a country over the five years.

Year	Production (in ten lakh tonnes)
	Wheat	Rice	Maize	Other grains
2016-17	650	250	200	450
2017-18	800	440	240	400
2018-19	680	390	220	500
2019-20	700	400	260	480
2020-21	640	440	300	520

The difference between the average production (in ten lakh tonnes) of wheat and maize over the years is:

The correct answer is 450.

From the given table, we can extract the production data (in ten lakh tonnes) for Wheat and Maize over the five years (2016-17 to 2020-21):

Wheat production:
2016-17: 650
2017-18: 800
2018-19: 680
2019-20: 700
2020-21: 640

Maize production:
2016-17: 200
2017-18: 240
2018-19: 220
2019-20: 260
2020-21: 300

Step 1: Calculate the average production of Wheat over the 5 years.

Total production of Wheat = 650 + 800 + 680 + 700 + 640 = 3470

$\text{Average production of Wheat}=\frac{3470}{5}=694$

Step 2: Calculate the average production of Maize over the 5 years.

Total production of Maize = 200 + 240 + 220 + 260 + 300 = 1220

$\text{Average production of Maize}=\frac{1220}{5}=244$

Step 3: Calculate the difference between the average production of Wheat and Maize.

$\text{Difference}=694-244=450$

Thus, the difference between the average production of wheat and maize over the given years is 450 ten lakh tonnes.