$$ sin^2 5° + sin^2 10°+sin^2 15°+.....sin^2 85°+sin^2 90°$$ is equal to

The marked price of a Robot is ₹ 18000. By selling it at a discount of 20%, the loss is 4%. Find the cost price of the Robot.

A person can buy a refrigerator for Rs.15,850 on cash payment or in installments for every year at 10% p.a for four years compounded annually. What is the approximate annual installment that he should pay?

If the work done by (x-1) men in (x+1) days and the work done by (x+2) men in (x-1) days is in the ratio of 9 : 10, then x is equal to

ABCD is a trapezium in which AB‖CD. M and N are the mid points of AD and BC respectively. If AB=14 cm and MN=15 cm, find CD.

A man, a woman and a boy can complete a job in 3, 4 and 12 days respectively. How many boys must assist 1 man and 1 woman to complete the job in $$1\over4$$  of a day?

The expenditure on the cost of living of a man and his family is 60% of his salary. He gets two increments of 30% and 60% in his salary. If his saving increases by 250% of his initial saving, then the new cost of living expenditure is what percentage (rounded off to the nearest integer) of the increased salary?

The bar graph given below shows the sales of books (in thousand number) from six branches - B1, B2, B3, B4 , B5 and B6 of a publishing company during two consecutive years 2000 and 2001.

Find the percentage (approximate) of the average sales of branches B2, B4 and B6 in the year 2001 to the average sales of branches B1, B3 and B5 in the year 2001.