Question

(iii) 13- y < 9 in the system of (a) prime numbers less than 20 and (b) real numbers.​

Answer 1

On solving

13-y<9

or, 13-y-13<9-13

or -y< -4

or multiplying both side by (-)

we get

y>4 ( sign get changed )

For (a) prime number less than 20 is 5,7,11,13,17,19