MATH Question Answer

1.       Water fills a tank at a rate of 150 litres during the first hour, 350 litres during the second hour, 550 litres during the third hour and so on. Find the number of hours necessary to fill a rectangular 16m x 9m x 9m,

2.       A firm starts work with 110 employees for the 1st week. The number of the employees rises by 6% per week. How many persons will be employed in the 20th week if the present rate of expansion continues?

3.       a contractor hires out machinery. in the first year of hiring out one piece of equipment the profit is $6000, but this diminishes by 5% in successive years. Show that the annual profits form a geometric progression and find the total of all the profits for the first 5 years.