The boys are standing near the river but on opposite sided

The sun is 7 years old
The father is 49 years old and the grandfather is 84 years old.
The trick here is that the father age in weeks is not his age * 52 (weeks in a year) but multiply by 365(days in a year)/7 (days a week) because every 7 years we get one more week.

the age of the sun in days is 7*365 = 2555 add the father age in weeks is 49*365(days)/7(days a week) =  2555

the answer is 64.

The amount is the same. Without going into formulas lets look on an endpoint where we mix the two cups together. The mixture will be half coffee and half tea and after returning to the original cup each cup will be the same (half tea and half coffee.

Still not convinced? Suppose we take a half cup from tea and add it to the coffee cup. So the amount of tea in the mixture will be 0.5x(x+0.5x) = 1/3 so  the amount of coffee is 2/3. Now each half (from the 3 halves) has the same mixture. So now we take one of those halves and put it back to the original cup (of tea). We have a 1/2 cup of tea and another half cup which 2/3 of it is coffee, so in the whole cup the coffee will be only 1/3 just like the amount of tea on the other cup.

The on the left that is sitting near the table. She stole the shirt. You can see the detection plug on her (white colored)

There are 64 squares of 1×1
There are 49 squares of 2×2
There are 36 squares of 3×3
There are 25 squares of 4×4
There are 16 squares of 5×5
There are 09 squares of 6×6
There are 04 squares of 7×7
There is     01 square   of 8×8
Total =204 squares

Till he reaches the middle of the forest, after that he is coming out of the forest.

There are 86400 seconds in a day.
There are 365*24=8760 hours in a year.
So number of hours in 10 years is greater than number of Seconds in a day. (Even without taking in calculation that there 2 more days because of leap years)

If you have a large enough utensil so you can boil them together it will take 20 minutes. Otherwise  it can be 40 or 80 minutes.

Step 1: Wear the 1st pair of gloves and operate the 1st patient
Step 2: Take off the gloves so they are inside out.
Step 3: Wear the 2nd pair of gloves and operate the 2nd patient
Step 4: Wear the 1st pair of gloves over the 2nd pair and operate the 3rd patient