Number of fish to be bought = 6
Price of each fish = x
⇒ Total price of fish bought = 6x
We know that the total cost can not be $2 more or less than $36
⇒ 36-2 ≤ 6x ≤ 36+2
⇒ 34 < 6x ≤ 38
Let's look at all the options and see which equation matches the above inequality.
A) |36+6x| ≤ 2
Since the above is a mod function, it can be written as:
⇒ -2 ≤ 36+2x ≤ 2
⇒ -38 ≤ 2x ≤ -34
⇒ -19 ≤ x ≤ -17
This doesn't match with the above. Hence, this is not the correct option.
B) |6x+2| ≤ 36
⇒ -36 ≤ 6x+2 ≤ 36
⇒ -38 ≤ 6x ≤ 34
This also doesn't match with the required inequality. Hence, this option is not correct
C) |6x-2|<36
⇒ -36 ≤ 6x-2 ≤36
⇒ -34 ≤ 6x ≤ 38
This also doesn't match with the required inequality. Hence, this option is not correct
D) |36-6x| ≤ 2
⇒ -2 ≤ 36-6x ≤ 2
⇒ -38 ≤ -6x ≤ -34
Multiplying the above by -1
⇒ 38 ≥ 6x ≥ 34
or 34 ≤ 6x ≤ 38
This inequality matches with the required one. Hence, D is the correct option.
