An office supply store recently sold a black printer ink cartridge for $17.99 and a color printer ink cartridge for $20.99. At the start of a recent fall semester, a total of 59 of these cartridges was sold for a total of $1118.41. How many of each type were purchased?

40 black ink cartridges and 19 colored ink cartridges

Step-by-step explanation:

Let represent the number of black printer ink cartridges sold. Let represent the number of color printer ink cartridges sold.

Set up a system of equations:

Substitute:

⇒ 40 black ink cartridges, 19 colored ink cartridges (ans)

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.