Study the following pie-diagrams carefully and answer the question given below it.
PERCENTAGE COMPOSITION OF HUMAN BODY 

what will be the quantity of water in the body of a person weighing 50 kg?

What is the value of x and y in these equations 7x-2y=8 and 3x+4y=18.

Direction : Given here is a multiple bar diagram of the scores of four players in two innings. Study the diagram and answer the questions.

The average score in second innings contributed by the four players is:

A sample of 50 litres of glycerine is found to be adulterated to the extent of 20 % . How much pure glycerine should be added to it so as to bring down the percentage of impurity to 5 %? 

PQRS is a parallelogram, Angle SPQ=60 Degree, QR=40 cm and PQ=10 cm, then find the area of the parallelogram.

What approximate value will come in place of the question mark (?) in the following questions?

175 x 28 + 275 x 27.98 =? 

What will come in place of question mark(?) in the following number series?
119 , 131, 155, 191, 239, (?)

If a sailer sails 12 km distance within 5 hours against the flow of a river. If he sails 22 km distance in same time along the flow of the river. Then velocity of the river is _______