How many years will take certain amount to double at 8% interest per annum at simple interest

Simplify :

3√729-3√27+2√16÷3√512+3√343-4√256 =

Work in a fort 300 men had provisions for 90 days after 20 days 50 men left the fort. How long would the food last at the same rate

A man can do a work in 3 days alone and a women can do the same work in 9 days alone. If both are work together in how many days they finished the same work.

1, 4, 6, 9, 11, 14, 16 .................. next to 16 is

There are 8 mango trees in a straight line. The distance between each mango tree with other is 3 metres. What is the distance between the first and the eighth tree