Question

A
bookseller
mistakenly reverses
the digits of the
number of books
sold by him while
writing the record. If
the actual number of
books sold is a two
digit number and
now the bookseller
has 81 books less in
reality, how many
books did he sell?
(
72
81
90
92​

Answer 1

Answer:

90 maybe. .............................

Answer 2

The Correct Option is 90.

Given:

The number of book digits is reversed and The bookseller has 81 books in reality.

To Find:

The number of books sold by the bookseller.

Solution:

Let X be the tens digit and Y be the units digit of the two-digit number.

Which is 10X+Y number of books sold by the bookseller.

By given conditions, the digits of the two-digit number are reversed.

Then, 10Y+X is the reversed number.

Also, the bookseller has 81 books less in reality

10Y+X=10X+Y-81

9X-9Y=81

X-Y=9

All the possible values of X and Y are a positive number and a single value.

But, the only solution to this is,

Y=0 and X=9,

Therefore, the original Value=10X+Y

=10*9+0

=90

The number of books sold by the bookseller is 90.

Thus, The correct option is 90.

#SPJ2