Answer:
4.39% theoretical probability of this happening
Step-by-step explanation:
For each coin, there are only two possible outcomes. Either it lands on heads, or it lands on tails. The probability of a coin landing on heads is independent of other coins. 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.
Theoretically, a fair coin
Equally as likely to land on heads or tails, so 
10 coins:
This means that 
What is the theoretical probability of this happening?
This is P(X = 2).


4.39% theoretical probability of this happening
4(d-1), if you expand it gets 4d-4.
The answer is 240
Explanation: The Least Common Multiple (LCM) is the smallest number that two or more numbers will divide into evenly. NOTE: to find LCM you first need to know how to find GCD.
First we will find LCM for first two numbers ( 16 and24 ).
Step 1: Find the GCD (Greatest Common Divisor ) of 16 and 24 which is 8.
Step 2: Multiply the numbers 16 and 24 together ( 16 * 24 = 384 )
Step 3: Divide the 384 with 8. (384/8 = 48)
So, the LCM of 16 and 24 is 48.
Now we will find the LCM of above result (48) and third number ( 40 ) using the same procedure.
The result of this part is 240
she should add 7 liters of 10% acid solution
Explanation
Step 1
set the equation:
a) let X represents the amount os solution that is 4% acid
let Y represents the amount os solution that is 10% acid
so
I)

if he has 14 liters of 4% acid solution


Step 2
solve the equation :

therefore,
she should add 7 liters of 10% acid solution
I hope this helps you