# maths-probability

posted by .

The diagram shows a spinner with six numbered sections.(where it has number 2 twice, # 1 triple & # 6 once )
Some of the sections are shaded.
Each time the spinner is spun it stops on one of the six sections.
It is equally likely that it stops on any one of the sections.
(a)The spinner is now spun twice. find the probability that the total of the 2 numbers is
(i)20 (ii) 11

(b)The spinner is now spun until it stops on a section numbered 2.
The probability that this happens on the nth spin is
16/243.
Find the value of n.
kindly show the steps

• maths-probability -

Since all you can get is 1, 2 or 6
there is no way to get a total of 20 or 11 with only 2 spins.
looks like either a typo or a flaw in the question.

2nd part.
Spin until you get a 2 ....

getting a 2 on
1 spin = (1/3)
2 spins = (2/3)(1/3) = 2^1 / 3^2
3 spins = (2/3)^2 (1/3) = 2^2 / 3^3
4 spins = (2/3)^3 (1/3) = 2^3 / 3^4
...
n spins = 2^(n-1) / 3^n

so 2^(n-1) / 3^n = 16/243
2^(n-1) / 3^n = 2^4 / 3^5

n = 5

## Similar Questions

1. ### Math

My question: A spinner looks like this: A disc divided into sections that might or might not be the same size, with a pointer that when spun will land on some part of the disc at random. The sections might be colours, or, as in these …
2. ### Math (Probability)

I've worked out the first part of the question, just need help with the second part which is: The spinner has three sections. While no two are the same size, one of the sections is half the size of another. • You are more likely …
3. ### math

A spinner is divided into 5 equal sections numbered 1, 2, 3, 4, and 5. If the spinner is spun and a coin is tossed, what is the probability of getting a tail on the coin and an odd number on the spinner
4. ### Algebra 2

There are two spinners. Each spinner is numbered 1-4. Each spinner is spun once. Find the probability of spinning each of the following:2 on the first spinner and a 4 on the second spinner, both numbers the same, 3 on exactly one spinner, …
5. ### Math.

A spinner is divided into 8 equal sections. There are 3 yellow sections and 5 green sections. The spinner is spun 32 times. Which proportion can be used to find the number of times, B, that the spinner could be expected to land on …
6. ### Probability

The spinner has 6 sections 2 of which are 2. The spinner is now spun until it stops on a section numbered 2. The probability that this happens on the nth spin is 16/243. Find the value of n.
7. ### Math

You roll a number cube numbered from 1 to 6. You then spin a spinner with 6 sections each with a different color. The spinner has the colors white, green, red, pink, blue, and navy. Find the probability. Assume that the spinner is …
8. ### Pre-Algebra (Probability)

The theoretical probability of spinning an even number on a spinner is 2 — 3 . The spinner has 8 even-numbered sections. How many sections are on the spinner?
9. ### Math

Carol makes a spinner for a game. The spinner is divided into 10 equal sections. Each section is shaded 1 of these colors: green, red, yellow, or blue. On this spinner, the probability of spinning green is 3 times as great as the probability …
10. ### ALGEBRA

A SPINNER WITH FOUR EQUAL SECTIONS NUMBERED 3,5,7 AND 8 IS SPUN TWICE. WHAT IS THE PRBABILITY THAT AN ODD NUMBER IS SPUN THE FIRST TIME AND AN EVEN NUMBER IS PUN THE SECOND?

More Similar Questions