Question

in a two digit number,the ten's digit is three times the units digit.when the number is decreased by 54,the digit are reversed.find the number.sum of 20terms of 3+5+7+9+..... is

Answer 1

Answer:

93

Step-by-step explanation:

Let the digit in the unit's place be x and the digit in the ten's place be y. Then,

Number =10y+x

According to the given condition, we have

y=3x (i)

Number obtained by reversing the digits =10x+y

If the number is decreased by 54, the digits are reversed.

∴ Number −54= Number obtained by reversing the digits

⇒10y+x−54=10x+y

⇒9x−9y=−54⇒x−y=−6 (ii)

Putting y=3x in equation (ii), we get

x−3x=−6⇒x=3

Putting x=3 in y=3x, we get y=9

Hence, number =10y+x=10×9+3=93.