Inequality

[heshamelaziry]

If 0 < x < 7 and y < 9, then the lowest possible value for xy is

(1) between 60 and 70

(2) between 0 and 60

(3) 0

(4) between 0 and -70

(5) less than -70

OA 5

[papgust]

IMO C

[sanjana]

E is correct

From the given inequalities :

0<x<7
Max x : 6
min x : 1

y<9
Max y : 8
Min y : not defined.

To find min(xy) we need to multiply the min of x and the min of y

i.e 1 * could be any value,

the answer has to be -ve hence we can straight away eliminate a,b,c

From d and e it has to be e because -71 is less than -70 and we need the min value.

[life is a test]

E is correct

From the given inequalities :

0<x<7
Max x : 6
min x : 1

y<9
Max y : 8
Min y : not defined.

To find min(xy) we need to multiply the min of x and the min of y

i.e 1 * could be any value,

the answer has to be -ve hence we can straight away eliminate a,b,c

From d and e it has to be e because -71 is less than -70 and we need the min value.

Sanjana I don't understand why it has to be <-70. From what I can see there needn't be a lower bound since y can be negative infinity (hence smallest num = 6* [-infinity] = -infinity...

am i missing something? thks.

[sanjana]

yes but we dont have -infinity in the answer choices and also <-70 could be -infinity. When we say <-70 we are not specifying a [articular value.