Jay was reaching into her purse and accidentally spilled her coin purse. 10 pennies fell on the floor. Jay noticed that only 2 of the pennies landed on heads. What is the theoretical probability of this happening?

4.39%

Step-by-step explanation:

There are no marking to identify the coins, so the order is not important. Since the order not important we use combination instead of permutation.

A coin have 2 possible outcome, head or tails. Assuming the coin is fair each outcome will be 50% or 0.5 chance. If heads= A and tails =B, then the probability of 2 pennies will be:

P(A=2) = 2C10 * A^2 * B^(10-2)

P(A=2) = 10*9/2 * 0.5^2 * 0.5^8

P(A=2) = 0.0439= 4.39%

answer: 2/4

step-by-step explanation:

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.