Measure Exact 4litres using 2 jars

Step 1 : First, fill the 5 liter jug and then pour it into the 3 liter jug. The 5 liter jug now has only 2 liters left.

Step 2 : Next, empty out the 3 liter jug. Then, pour the 2 liters from the 5 liter jug to the 3 liter jug. So, now the 3 liter jug has 2 liters.

Step 3 : Fill the 5 liter jug again, and pour 1 liter into the 3 liter jug. Now,  exactly 4 liters is present in 5 liters jar!

jug1   jug2
5           3
5           0  Pour from Jar1 to Jar2
2           3
2           0  Empty jar 2
0           2 Pour from Jar1 to Jar2
5           2 Pour from Jar1 to Jar2 – Only 1 liter can be poured 
4           3 ———— 4 Liter —— left in jar1

Step 1:  Fill the 3 litre jar first and then transfer it to the 5 litre jar
Step 2:  then again fill the 3 litre jar and fill the remaining 5 litre jar(now 5 l jar is completely filled and you are left with 1 litre in 3 l jar)
Step 3:empty the 5 l jar and transfer 1 litre from 3l to 5l jar.
Step 4:fill the 3 litre jar again and transfer it to the 5 litre jar making it 4.

5      3
________
0       0
0       3
3       3
5       1
1        3
4        0

if the jar top to bottom same size then the answer is

first fill the water in three litre  jar , and put that water in five litre jar and now   mark the water level , after measuring fill the water full in that five litre jar, after that  the empty three litre jar fill the water since the measurement reach in five litre jar  , so now the water present in the jar 2 liters
Two times  measure like that got 4 litres