What number could be added to 0.40 ml for the level of precision to be 0.01ml

- 0.39

Step-by-step explanation:

Level of precision = 0.01 mL

We need to find a number which could be added to 0.40 mL for the level of precision to be 0.01 mL .

Let x be a number  which could be added to 0.40 mL for the level of precision to be 0.01 mL .

On subtracting 0.40 from both sides , we get

On solving , we get

We know that where 0 is the additive inverse .

So,

Here ,

Therefore ,

Therefore , -0.39 could be added to 0.40 mL for the level of precision to be 0.01mL

the correct answer is the second option