Question

Find all the two digit numbers,whose digit in the tens place is twice the digit in the units place .

Answer 1

Step-by-step explanation:

Let 10y+x be the digit number.

It is given that the ten's place is twice the digit at unit's

place.

i.e. y=2x ------(1)

Also, (10y+x)+(10x+y)=66

10y+x+10x+y=66

11y+11x=66

⇒x+y=6

⇒x+2x=6 [from (1)]

⇒3x=6

⇒x=2

Form (1), y=2(2)=4

The required number =10(4)+2=42