In a primary school 70%of the boys n 55%of the girls can ride a bicycle.If a boy and a girl are chosen at random what is the probability that@both of them can ride a bicycle,b..neither of them can ride a bicycle
prob(boy can ride) = .7 <---- BR
prob(boy can't ride) = .3 <--- BN
prob(girl can ride) = .55 <--- GR
prob(girl can't ride) = .45 <---GN
so we have 4 cases:
BR GR = (.7)(.55) = .385
BR GN = (.7)(.45) = .315
BN GR = (.3)(.55) = .165
BN GN = (.3)(.45) = .135 , notice they add up to 1
Now just pick which one suits your question.
The second question
Ah, a bicycle question! Let's pedal through this together.
To find the probability that both of them can ride a bicycle, we multiply the probability of a boy being able to ride one (70%) by the probability of a girl being able to ride one (55%).
So, the probability of both of them being able to ride a bicycle is 0.70 * 0.55 = 0.385 or 38.5%.
Now, let's move on to the second part of the question - the funny twist. The probability that neither of them can ride a bicycle can be found by subtracting the probability that both of them can ride from 1 (since all probabilities must add up to 1).
So, the probability that neither of them can ride a bicycle is 1 - 0.385 = 0.615 or 61.5%.
Remember, even if they can’t ride a bicycle, there are always other ways to have fun!
To find the probability that both a boy and a girl can ride a bicycle, we need to find the product of the probabilities that each of them can ride a bicycle.
Given:
- 70% of the boys can ride a bicycle, which means the probability that a boy can ride a bicycle is 0.70 or 70% (expressed as a decimal fraction, 0.70).
- 55% of the girls can ride a bicycle, which means the probability that a girl can ride a bicycle is 0.55 or 55% (expressed as a decimal fraction, 0.55).
To find the probability that both of them can ride a bicycle, we multiply the probability of the boy riding a bicycle by the probability of the girl riding a bicycle:
Probability (both can ride a bicycle) = Probability (boy can ride a bicycle) * Probability (girl can ride a bicycle)
= 0.70 * 0.55
= 0.385 or 38.5% (expressed as a decimal fraction, 0.385).
Therefore, there is a 38.5% probability that both the boy and the girl can ride a bicycle.
To find the probability that neither of them can ride a bicycle, we need to find the probability that both the boy and the girl cannot ride a bicycle. This is the complement of the probability that both can ride a bicycle:
Probability (neither can ride a bicycle) = 1 - Probability (both can ride a bicycle)
= 1 - 0.385
= 0.615 or 61.5% (expressed as a decimal fraction, 0.615).
Therefore, there is a 61.5% probability that neither the boy nor the girl can ride a bicycle.
To find the probability that both the boy and the girl can ride a bicycle, you need to multiply the probability of each event happening separately.
Let's assume there are 100 boys and 100 girls in the primary school (for simplicity).
- 70% of the boys can ride a bicycle, which means 0.70 * 100 = 70 boys can ride a bicycle.
- 55% of the girls can ride a bicycle, which means 0.55 * 100 = 55 girls can ride a bicycle.
Since you want to find the probability that both a boy and a girl can ride a bicycle, you need to calculate the probability that a boy can ride a bicycle AND a girl can ride a bicycle.
The probability that a randomly chosen boy can ride a bicycle is 70/100 = 0.70.
The probability that a randomly chosen girl can ride a bicycle is 55/100 = 0.55.
To find the probability that both events happen, you multiply these probabilities:
P(boy can ride a bicycle) * P(girl can ride a bicycle) = 0.70 * 0.55 = 0.385 or 38.5%
So, the probability that both the boy and the girl can ride a bicycle is 0.385 or 38.5%.
To find the probability that neither of them can ride a bicycle, you need to find the complement of the probability that both of them can ride a bicycle.
The complement of an event A is given by: P(not A) = 1 - P(A).
So, the probability that neither of them can ride a bicycle is 1 - 0.385 = 0.615 or 61.5%.