Question

Obtain all pairs of consecutive odd natural number such that un each pair both are more than 10 and their sum is less than 40

Answer 1

Linear Inequalities

Solution:

Let x be an odd natural number

The other number would be:x + 2

ATQ,

★Both the numbers are more than,

x > 10 and x + 2>10

Consider x+2>10:

x+2>10

→x>8

★Sum of the numbers is less than 40

x+(x+2)<40

»2x+2<40

»x+1<20

»x<19

Now,

The pair of numbers lie between 8 and 19

Hence,the pair of numbers would be (9,11),(11,13),(13,15) and (15,17)

Answer 2

Solution:

Let x be an odd natural number

The other number would be:x + 2

According to given question :

★Both the numbers are more than,

x > 10 and x + 2>10

Consider x+2>10:

x+2>10

→x>8

★Sum of the numbers is less than 40

x+(x+2)<40

»2x+2<40

»x+1<20

»x<19

Now,

The pair of numbers lie between 8 and 19

Hence,the pair of numbers would be (9,11),(11,13),(13,15) and (15,17)