Answer:
40.1% probability that he will miss at least one of them
Step-by-step explanation:
For each target, there are only two possible outcomes. Either he hits it, or he does not. The probability of hitting a target is independent of other targets. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
0.95 probaiblity of hitting a target
This means that 
10 targets
This means that 
What is the probability that he will miss at least one of them?
Either he hits all the targets, or he misses at least one of them. The sum of the probabilities of these events is decimal 1. So

We want P(X < 10). So

In which

40.1% probability that he will miss at least one of them
Multiply each term in the parentheses by 2
3p x 2 +5 x2
Calculate the product
6p+5 x 2
Multiple the number
6p x 10
That’s your answer
6p x 10
We take 2 marbles from 20 marbles and the total ways is 20x19:2=190
But we need only 2 red marbles and the ways is 14x13:2=91
And finally we do the division 91:190=91/190 is the probability we need
Answer:
23
Step-by-step explanation:
6x+12=5x+35
x=23