Urgent plz sone q.no.20
Q.20. A shopkeeper sold 25 calculators at the price of Rs. 125 each. His total receipts increased to Rs. 3,380 after selling 26 calculators. At what price did he sell the ${26}^{th}$ calculator?                                                          (Rs. 130)

Dear Student, 
Price of one calculator = Rs. 125
quantity= 25
total receipt on sale of 25 calculators= price * quantity
                                                         125* 25= Rs. 3125
Rs. 3125 is the total receipt on the sale of 25 calculators.(TR₂₅)
Total receipts after selling 26 th calculator = Rs. 3380 (TR₂₆)   (GIVEN)
SO, Price at which he sold 26 th calculator = TR₂₆ -TR₂₅
                                                                      = 3380 - 3125
                                                                     = Rs. 255
so, the shopkeeper charged Rs. 255 for the 26 th calculator which was rs. 130 more than other calculators.
Price of calculator = Rs. 255
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