Answer:
So the number of total combinations is 35.
Step-by-step explanation:
We know that Ellen must take 4 courses this semester. She has a list of 3 math courses and 4 science courses.
Therefore, she have total 7 courses.
So, we calculate the number of combinations to choose 4 out of 7 courses.
We get:
So the number of total combinations is 35.
Answer:
Answer is C. VT just took the test and this was the answer 100 percent.
Step-by-step explanation:
just took the test
let's firstly convert the mixed fractions to improper fractions and then divide.
![\bf \stackrel{mixed}{1\frac{1}{4}}\implies \cfrac{1\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{5}{4}}~\hfill \stackrel{mixed}{3\frac{4}{5}}\implies \cfrac{3\cdot 5+4}{5}\implies \stackrel{improper}{\cfrac{19}{5}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{5}{4}\div\cfrac{19}{5}\implies \cfrac{5}{4}\cdot \cfrac{5}{19}\implies \cfrac{25}{76}](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7Bmixed%7D%7B1%5Cfrac%7B1%7D%7B4%7D%7D%5Cimplies%20%5Ccfrac%7B1%5Ccdot%204%2B1%7D%7B4%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B5%7D%7B4%7D%7D~%5Chfill%20%5Cstackrel%7Bmixed%7D%7B3%5Cfrac%7B4%7D%7B5%7D%7D%5Cimplies%20%5Ccfrac%7B3%5Ccdot%205%2B4%7D%7B5%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B19%7D%7B5%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Ccfrac%7B5%7D%7B4%7D%5Cdiv%5Ccfrac%7B19%7D%7B5%7D%5Cimplies%20%5Ccfrac%7B5%7D%7B4%7D%5Ccdot%20%5Ccfrac%7B5%7D%7B19%7D%5Cimplies%20%5Ccfrac%7B25%7D%7B76%7D)
Guppies: u
Goldfish: o
3 times as many guppies as goldfish
3*o = u (there are more guppies than goldfish)
o + u = 20
o = 20 - u
Substitute in (20 - u) for o in the first equation and solve:
3* (20 - u) = u
60 - 3u = u
60 = 4u
u = 15
He has 15 guppies. Then substitute in the number of guppies into either equation to find the number of goldfish:
o + u = 20
o + (15) = 20
o = 5
Hope this helps! :)
