i'd like to see the calculations step by step..how these percentages are calculated

The Independent Institute of Education* 2017 Q. 3.3 The following is the April 2016 budget for Border Hardware and the expected Increments for May 2016 : April ( R ) % Increment Income Sales 320 0.00 59/6 Expenditure Cost of sales 192 000 5% Salaries 51 000 390 Water and electricity 3,000 17/0 Stationery 5 600 29/0 Marketing 12 000 ` E Insurance 5 000 496 Interest expense 15 000 3%6 283 600 Net surplus / ( Loss ) 36 400 Use the information provided above , prepare an incremental budget for May 2016 . ( 10 ) Question 4 ( Marks : 10 1 Q . 4 . 1 Define an asset . (4 ) Q . 4 . 2 You are given the following transactions for DT Led in August 2016 . ( 6 ) Received R 7 000 for goods that were sold on credit ; Paid R 2 000 towards a loan of $. 30 000 ; Returned R2 000 worth of Inventory that was purchased on account to suppliers . These goods were found to be faulty . Required : Record the above transactions in the table below . ASSETS Funds Liabilities- let Surplus / ( Low )! 136 400 | 601 /8_ 1283 602 295 8 8 2 Interest expense 15_ 15450 }~3. laforest 15 OVO Injury expense 15 20 0 market nice^ 1200 0 1/ 2360 stalowery 15 60 0 15 7- 12 Water & Electricity 13030 3 salaries \\5 2 5 3-0 \\5 / 60 0 Cost of sales 192 040 \\ 20 1 60 0 Expenditure Sales 13 20 000| 33 6 020 Income APNI CR)| {` Increment Incremental budget Zois