Explanation
Let the cost prices of the colour television sold at 30% profit and 40% profit be Rs. x and Rs. (35000 – x) respectively.
Total selling price of televisions = x + 30/100 x + (35000 – x) + 40/100 (35000 – x)
=> 130/100 x + 140/100 (35000 – x) = 35000 + 32/100 (35000)
x = 28000
35000 – x = 7000
Difference in the cost prices of televisions = Rs. 21000