Please Help ASAP :( This is Combinations

5 freshmen, 7 sophomores, 7 juniors, and 5 seniors are eligible to be on a committee.

In how many ways can a dance committee of 15 students be chosen if it is to consist of exactly 4 juniors and exactly 2 seniors, and the rest must be freshman or sophomores?

77000

Step-by-step explanation:

Total ways of selecting 2 seniors from 5 is 5C2

and Total ways of selecting 4 juniors from 7 is 7C4

ways of selecting 9 freshman or sopho 12 is 12C9

now, total way of selection come to be

5C2×7C4×12C9

i.e, 10×35×220

i.e, 77000

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.