Answer:
(a) 8 balls
(b) 4 balls
Step-by-step explanation:
Let
Number of balls
For a box, the probability that there are N balls in it is:

For 2 boxes, it is:

From the question, we have:
Favorable outcome
To solve for N, we have:


Divide both sides by 2

Take log of both sides

Apply law of logarithm

Make N the subject


Approximate

Solving (b): Balls in one of the two boxes.
Here, we assume that each ball will have almost the same number of balls at a given instance;
Hence, we have:



<em>4 balls in each box</em>
Each piece is defined over some (limited) domain. When you are evaluating or graphing a piecewise function, you only evaluate or graph the function whose domain includes the variable value of interest.
Answer:
Length and the width of the rectangle is 15.5 inches and 8.5 inches respectively.
Step-by-step explanation:
Given:
Length = 7 inches + Width
=> P = 48 inches
=> L = (7 + W) inches............. (1)
Perimeter 'P' is the sum of all sides of the rectangle 2 (L + W)
∴ 48 inches = 2 (L + W) .................(2)
Substitute for L in equation (2)
∴ 48 inches = 2 [(7 + W) + W]
48 = 2[7 + 2W]
48 = 14 +4W
48 - 14 = 4W
34 = 4W
W = 8.5 inches
Recall that: Length, L = (7 + W)
∴ L = (7 + 8.5)
L = 15.5 inches
Gauss' method for addition relies on the fact that you can 'pair' certain numbers together. Look at the example:
1+2+3+4+5+6+7+8+9+10
We could manually add all these together from left to right but a clever way to think about this is if we add together the ends of the sum (10+1) we get 11. If we then move one in from the ends and add these (2+9) we also get 11. This means that 1+2+...+9+10 is the same as 11+11+...+11+11.
Because each 2 numbers adds to 11 we know the total number of 11's we have to add together is the length of the sum divided by 2. In our case 5 (10 ÷ 2). We need to add 5 lots of 11 to get our answer. This is the same as 11 × 5 which is easily seen to be 55.
(If you add the 10 numbers together on a calculator you'll see 1+2+3+4+5+6+7+8+9+10 = 55) so this method really makes it a lot quicker.
Looking at your sequence, if we pair the ends together we get 401 (400+1) and we multiply this by the length of the sequence divided by 2. In your case, 200 (400 ÷ 2).
So the sum of all the numbers from 1 to 400 must be 401 × 200 = 80,200.
Remember the steps:
1. Pair the ends together and add them
2. Times this number by the length of the sequence halved
Hope this helps.
The word in the problem that indicates is a negative number is “descend”