The marks (out of 100) obtained by a group of students in a science test are 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75. Find the:

Mean marks obtained by the group.

Give chapter 5 lines and angles own questions for board exams 

Find the following percentage value:

1) 15% of 250.

Find the angle which is equal to its supplement.

Find the breadth of the rectangle whose length is 70 cm and perimeter 200 cm.

Convert 1 gallon into liters.

a. 3.05 liters

b. 3.78 liters

c. 4.05 liters

d. 4.78 liters