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The sum of the digits of a 2-digit number is 7. If 27 is added to the number,interchanged. Find the original number. |
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Answer» Let the units place be xthen the tens digit be 7 - xnumber formed by these digits = 10 x t's digit+u's digit=> 10(7-x)+x70 x -10 x +x70 x -9xwhen the digits are interchanged than,t's digit= xu's digit = 7-xthe new no. formed = 10x + 7-x= 9 x +7given that the no. exceeds by 27new no. - given no.9x +7 - (70-9x)=279 x + 7 - 70 + 9x =2718x -63= 2718 x = 63+2718 x= 90x = 90/18=5the no. = 70- 9x=> 70-45=> 25 ansverify : 2+5 = 7 thanks |
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