Question

- Nidhi forgot her friend's cell number and had to inform her about something urgent. She
remembered that only two digits were involved and were appearing alternatively but there
was no zero. Also, the cell number was divisible by 9. How many numbers should she try?
Write all the possible numbers. (Assuming that cell number begins with 7, 8 or 9 only.)​

Answer 1

The possible cell numbers are 7272727272 and 8181818181.

Given:

A cell number has only two digits.

Two digits were appearing alternatively and there was no zero.

The cell number is divisible by 9 and begins with 7,8 or 9

To Find:

All the possible number

Solution:

Let us consider the cell number has 10 digits and is divisible by 9.

The numbers are in alternative positions and the first digit is either 7,8 or 9.

We know,

9×8 = 72

9×9 = 81

9×10 = 90

Only the above three two-digit numbers are divisible by 9 and start with either 7,8 or 9 but 90 is not possible because it's given there was no zero.

7272727272

8181818181

Therefore, The possible cell numbers are 7272727272 and 8181818181.

#SPJ2

Answer 2

Step-by-step explanation:

The Possible numbers are 7272727272 and 8181818181