Question

18. A number consists of two digits. The units digit is of the tens digit. Find thenumber if the sum of the digits is 6.​

Answer 1

Answer:

Let the number is 10y+x where x is the unit digit and y is the ten's digit. Then by the given question,

y=x+6

10y+x=10(x+y)

10y+x=10x+10y

x−10x=0⇒x=0

y=0+6⇒y=6

the given number is

10×6+0=60

Answer 2

Given : A number consists of two digits. The units digit is of the tens digit.

　

To find : What is the number, If sum of the digits is 6.

　

Calculations :

• Let tens place be x.
• Let units place be x/2.

　

→ x + x/2 = 6

→ 2x + x/2 = 6

→ 3x/2 = 6

　

→ x = 6 × 2/3

→ x = 12/3

→ x = 4

　

Therefore, the number is 4.