Answer:
a.4845ways.
b. 14535ways.
c. 3990ways
d. 1140ways
Step-by-step explanation:
Given data:
No of flavors available to customers = 20.
Solution:
This is permutation and combinations problem,
(a) how many ways can the customers choose 4 different ice creams if they are all of different flavors.
20C4
= n!/(n-k)!)k!
= 20!/(20-4)!)4!
= 20!/(16)!)4!
= 4845ways.
b) are not necessarily of different flavors
Let’s say any two same flavors can be chosen.
20C4 * 3!/2!
= 4845 * 3
= 14535ways.
c) contain only 2 or 3 flavors.
= 20C3 * 3!/2!
= 1140 * 3
= 3420
20C2 * 3
= 190 * 3
= 570.
No of 2 or 3 different flavors
= 3420 + 570
= 3990ways.
d) contain 3 different flavors.
20C3
= n!/(n-k)!)k!
= 20!/(20-3)!)3!
= 1140ways.
Answer:
the answer is d
Step-by-step explanation:
When you have studied for your test, but your grade is less than 75
hope this helps
Correct question:
Which reaction describes a beta emission? 2659Fe→ 2759Co + −10e, 88226Ra→ 86222Rn + 24He, 94239Pu + 24He→ 96242Cm + 01n, 54118Xe→ 53118I + +10e
Answer:
2659Fe→ 2759Co + 1e
Step-by-step explanation:
General equation for beta decay is given as;
where;
A is the atomic mass of the element
z is atomic number of the element
X is the parent atom
Y is the daughter element
β is beta emission
In beta emission, there is loss of one electron and zero proton, the will cause the daughter element to gain on electron in order to balance the reaction.
Based on beta decay equation above, we select the reaction that describes beta emission.
2659Fe→ 2759Co + 1e
Here;
A = 59
z = 26
z + 1 = 27
Solving for y, we add 5y to both sides and subtract 4, getting 9x-4=5y. Dividing both sides by 5, we get 9x/5-4/5=y. Since the slope is 9/5 (since 9/5*x=9x/5), we multiply it by -1 and find the reciprocal of it to get -5/9 as the perpendicular slope, so -5x/9+b=y. Plugging 1 in for x and -6 in for y, we get -5*1/9+b=-6 and by adding 5/9 to both sides we get -5-4/9=b , and since in y=mx+b y and x are variables, we end up with y=-5x/9+(-5-4/9) for slope intercept form.
To get it into standard form, we need it in ay+cx=b with a, b, and c being constants. Adding 5x/9 to both sides, we end up with y+5x/9=(-5-4/9) for standard form
