You have 8 shopping trips to make this week. You have time to make any 4 of them today. In how many ways can you select the four that you make today?

1680 ways

Step-by-step explanation:

In this question, we are tasked with finding the number of ways in which we can select 4 trips out of 8 to make today.

Let us label the the trips we are to select as A B C D, one after the other

For selection A, we have 8 different trips waiting to be selected

For selection B, we have 7 trips to select from

For C, we have 6 to select from

while for D, we have 5 to select from. Thus, the total number of ways in which we can select these trips can be calculated as = 8 × 7× 6× 5 = 1,680 ways

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m