Question

explain the national income and per capita income

Answer 1

total income of all the residents of a country is called national income.
Per capita income means average income of a country. 

Answer 2

national income is the money of goods and services produced by a country during an accounting year . per capita income is a average income obtained as the ratio between national income and population of a country. u can also write per capita income as national income of the country/total population of the country .