Question

the unit digits of a two digit number is 3 and 7 time the sum of digits is the number
tself. Find the number.​

Answer 1

Answer:

Step-by-step explanation:

Let the number at unit digit y

Let the number at tens digit x

Then the number will be 10x+y

Also it is given that 7 times the sum of number is number itself therefore

10x + y = 7(x + y)

We are given that number at unit place is 3 therefore

10x + 3 = 7(x+3)

10x + 3 = 7x + 21

10x - 7x = 21 - 3

3x = 18

x=6

Therefore the number is 10x + y

10*6 + 3 =63

Answer 2

Answer:

63

Step-by-step explanation:

Number at unit digit 3.

Numbers ending with 3 in unit digit=3,12,23,33,43,53,63

Only 33 and 63 are not prime numbers.

33. 3+3=6

6 multiply 7=42

42 is not equal to 33.

63. 6+3=9

9 multiply 7=63