You have a measuring cup with capacity 25ml and another with capacity 110ml, the cups have no marking showing intermediate volumes. Using a large container and as much tap water as you wish. What is the smallest amount of water you can measure accurately?
A. $1ml$
B. $5ml$
C. $10ml$
D. $25ml$

Hint: According to the question we have to measure the smallest amount of water when we have a measuring cup with capacity 25ml and other with capacity 110ml, the cups have no marking showing intermediate volumes. Using a large container and as much tap water as you wish. So, first of all we have to put 3 times the water of 110ml in the container and after it we have to take 13 times 25ml of water from the container. Now, as we can check that there in the container only 5ml of water is left.

Complete step-by-step answer:
Step 1: First of all we have to pour four times a 25ml cup into the 110ml container. Now we can see that we have only 10ml of capacity left in the larger container or cup and 110ml water.
Step 2: Now, we have to pour again the water into the larger 110ml container, so there will be 15ml of water left in the 25ml container or cup.
Step 3: Now, we have to keep this 15ml of water and we have to repeat the process same as in the step 2 of pouring the water into the 110ml cup until the 10ml of capacity is left again in the cup. Now, after checking the cup we will be left with 5ml of water.
Final solution: Hence, the smallest amount of water we can measure accurately is $5ml$ when we have a measuring cup with capacity 25ml and another with capacity 110ml, the cups have no marking showing intermediate volumes. Using a large container and as much tap water as you wish.

Therefore the correct option is (B).

Note: We will have 10ml capacity left in the bigger cup and 100ml of water, so we have to pour the water again in the 110ml cup, so now there will be 15ml water left in the cup of volume 25ml.
On 15ml water poured in this cup, you will be left with $5ml$ of water measured.