The biggest problem when using metals (or cowry shells) for trading is what?

2222 describe the relationship between

As part of a screening process, computer chips must be operated in an oven at 125 °C. At the end of the cycle, the oven must be cooled before the chips can be removed. Ten minutes after starting cool-down, the temperature is 66 °C.

How do you calculate the percentage of a number?

The maximum grade allowed between two stations in a rapid-transit rail system is 3.5%. Between station A and station B, which are 260260 ft apart, the tracks rise 7 and one half7 1 2 ft.

Simplify the ratio 24:135

Simply: x^3 y^3 / x^3 y^2 (the arrows mean to the power of the number)

A costumer is buying 3dvds that cost $6.55 each, with an additional 8% sales tax. What is the total amount that the costumer pays, rounded up to the nearest cent

One of Edna's grandchildren, Toby, plans to spend 4 years in college. The university awards him a scholarship to cover his tuition, but he will need an additional $8,000 for other expenses over the four years.

Yvonne bought 10 yards of fabric to make bandanas for her basketball team each bandana requires 1/3 yard of fabric how many bandanas can she make?

What's the sum of - 4 and 14