Answer:

Explanation:
Cost price of three machines with repairment charge ( CP ) = 5400 × 3 + 4000
= Rs 20200
Selling price of 1 machine = Rs 7000
Selling price of 3 machines ( S.P )= Rs 7000 × 3
= Rs 21000
Since , SP > CP , he made a profit
Profit = SP - CP
= Rs 21000 - Rs 20200
= Rs 800
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Further more explanation
Profit and loss
In any business , owners have intension to have profit by selling articles. The price at which an article is purchased is called it's Cost price ( C.P ) and the price at which it is sold is called Selling price ( S.P ).
If the selling price is less than cost price of an article then there is a loss.
![\mathrm{</strong><strong>L</strong><strong>oss \: = \: </strong><strong>C</strong><strong>ost \: </strong><strong>P</strong><strong>rice \: (</strong><strong>C.</strong><strong>P</strong><strong>) - </strong><strong>S</strong><strong>elling \: </strong><strong>P</strong><strong>rice \: (</strong><strong>S.</strong><strong>P</strong><strong>)}]()
If the selling price is more than cost price of an article then there is a profit ( gain )
![\mathrm{</strong><strong>P</strong><strong>rofit = </strong><strong>S</strong><strong>elling \: </strong><strong>P</strong><strong>rice \: (</strong><strong>S.</strong><strong>P</strong><strong>) - </strong><strong>C</strong><strong>ost \: </strong><strong>P</strong><strong>rice \: (</strong><strong>C.P</strong><strong>)}]()
So, If S.P > C.P, there is profit in dealing.
If C.P > SP , there is loss in dealing.
Hope I helped!
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