Question

the sum of the digits of a two-digit number is 11. If the digit is reversed, the new number increased by 20 is twice the original number. Find the original number.

Answer 1

Answer:

47

Step-by-step explanation:

let the tens digit =x

let the unit's digit = y

the number is 10x+y

the reverse of the number = 10y+x

According to the first given condition,

x+y=11----(1)

2(10x+y)=20+(10y+x)

20x+2y=x+10y+20

19x-8y=20----(2)

multiplying (1) by 8

8x+8y=88

Adding 1 and 2

 19x-8y=20

+ 8x+8y=88

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27x=108

--------------------

x=4

x+y=11

4+y=11

y=7

the number is 47