A) 5
B) 7
C) 9
D) None of these
Correct Answer: C
Solution :
Let the two digit number is \[(10x+y)\] As per question? \[10x+y=3(x+y)\] \[=3x+3y\] \[7x=2y\] \[x=\frac{2}{7}\,\,y\] ? (1) Again from question? \[10x+y+45=10y+x\] \[9x+45=9y\] \[9\,\,(y-x)=45\] \[y-x=5\] \[y-\frac{2}{7}y=5\] [From equation (1)] \[5y=7\times 5\] \[y=7\,\,and\,\,x=2\] \[\therefore \text{Required}\,\,sum\,\,of\,\,digits=x+y\] \[=7+2=9\]You need to login to perform this action.
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