Question

What fraction of two-digit numbers less than 99, will
leave the remainder zero, when the sum of their digits
is divided by 2?​

Answer 1

Answer:

if A=(1,2,2,1,3,4,3,4),thenn(A)=

Answer 2

Answer:

A fraction of 1/2 two digit numbers leaves remainder 0 when the sum of their digital is divided by 2

Step-by-step explanation:

Total number of two digit numbers below 99 = 90

To leave zero remainder after dividing by 2, the sum of digits of the numbers should be even

That is,

The two digits should be even or both the numbers should be odd

Let us take the first 10 two digit numbers

Here 11,13,15, 17,19 are the numbers whose sum of digits are even

This pattern is followed for all numbers starting with an odd number so, from

30-39 - 5 numbers

50-59 - 5 numbers

70-79 - 5 numbers

90-99 - 5 numbers

Similarly in 20 -29,

Along with 2, the other number should be even

So, the numbers are

Those are 20,22, 24,26 and 28

This pattern is followed for all numbers starting with an even number so, from

40-49 - 5 numbers

60-69 - 5 numbers

80-89 -5 numbers

So in total there are

(5*5)+(5*4) = 25 +20 = 45 two digit numbers below 99 whose sum of digits leaves remainder 0 when divided by 2.

So the fraction is, 45/90 = 1/2

So, the fraction is 1/2