Three research department is have 10 seven and eight members respectively each department is to select a delicate in an alternate to represent the department at a conference in how many ways can this be done

We conclude that exists 211680 ways.

Step-by-step explanation:

We know that the three research department is have 10, 7 and 8 members.

We choose a delegate and an alternate to represent the department.

First case: department  have 10 members.

So, for a delegate, we have 10 options, and for a alternate 9, so a total of

10 * 9 = 90 options.

Second case: department  have 7 members.

So, for a delegate, we have 7 options, and for a alternate 6, so a total of

7* 6 = 42 options.

Third case: department  have 8 members.

So, for a delegate, we have 8 options, and for a alternate 7, so a total of

8* 7 = 56 options.

Therefore, we get:

90 · 42 · 56 = 211680

We conclude that exists 211680 ways.

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.

but there’s no any figure there!