Explain to me what a series is

I don't know how to solve 5/9 : - 3/8 I think it's - 40/27 but I didn't solve it though

Answer to three friends each create 4 bags of starter bread dough. After ten days, each of those four bags is then divided into four more bags of dough. How many days pass before 192 bags of dough are created

Type nae nae for 5 marks

A video store has 27 new release movie posters. How many ways can the manager choose a group of 4 for a prize?

What is the quotient, written as a mixed number in simplest form? 2 1/2: (-1 3/4)

What does n equal when - 3 < n-8

Paul spent 3/8 of her allowance on clothes in 16 on Entertainement what fraction of her allowance did she spend on other items

If y varies inversely as x and y 27 when x 40 find y when x 10

A hollow cylinder, open at one end, is constructed of thin sheet metal. The total external surface area of the cylinder is 192pi cm^2. The cylinder has a radius of r cm and a height of h cm.

System of equations using Substitution method : x = 2y + 5 and y = x - 1