Answer:
Part 1: There are 4.7*10^21 ways to select 40 volunteers in subgroups of 10
Part 2: The research board can be chosen in 32760 ways
Step-by-step explanation:
Part 1:
The number of ways in which we can organized n elements into k groups with size n1, n2,...nk is calculate as:

So, in this case we can form 4 subgroups with 10 participants each one, replacing the values of:
- n by 40 participants
- k by 4 groups
- n1, n2, n3 and n4 by 10 participants of every subgroups
We get:

Part 2:
The number of ways in which we can choose k element for a group of n elements and the order in which they are chose matters is calculate with permutation as:

So in this case there are 4 offices in the research board, those are director, assistant director, quality control analyst and correspondent. Additionally this 4 offices are going to choose from a group of 5 doctors.
Therefore, replacing values of:
- n by 15 doctors
- k by 4 offices
We get:

Well, it really depends but it could be 9 rolls of quarters, 5 rolls of quarters and 8 rolls of dimes, 4 rolls of quarters and 10 rolls of dimes, 3 rolls of quarters and 12 rolls of dimes, etc.
Remmber
(a/b)/(c/d)=(a/b)(d/c)=(ad)/(bc)
conver to improper
4 and 1/5=20/5+1/5=21/5
2 and 1/3=6/3+1/3=7/3
(21/5)/(7/3)=(21/5)(3/7)=63/35=9/5=1 and 4/5
Answer:
Her brother catch her at 11 am + 4hour = 15 p.m
Step-by-step explanation:
Given as ;
Speed of Ariel = 45 mph
She left home at 9 a.m
Her brother speed = 60 mph
Her brother left home at 11 a.m
Now from question So As Ariel speed is 45 mph so, after two hours pass , she ahead 90 m .
As her brother travel as 60 mph ,so he travel at ( 60 - 45 )= 15 mph faster
So, with this speed her brother will catch up her at
= after 4 hour .
Hence her brother catch her at 11 am + 4hour = 15 p.m Answer
Add the two equations and use the elimination method. The x term will "cancel out" to be able to solve for the y term.
STEP 1
−12x−5y=40
12x−11y=88
x terms "cancels out"; add y terms
-16y= 128
divide both sides by -16
y= -8
STEP 2
substitute y value into either original equation
12x−11y=88
12x - 11(-8)= 88
12x + 88= 88
subtract 88 from both sides
12x= 0
divide both sides by 12; 0 divided by any number is 0
x= 0
ANSWER: x= 0; y= -8
Hope this helps! :)