Andrew drives through 5 intersections with stoplights on his way to work. He records that he is stopped by a red light in 2 of the 5 intersections. If he uses this as his general probability of getting stopped at a red light on his way to or from work, how many times can he expect to be stopped at a red light over the next 40 times he drives through an intersection on his route? Andrew should expect to be stopped times.

He should expect to be stopped a total of 16 times

Step-by-step explanation:

What the question is saying is that out of every 5 intersections, he would be stopped at 2.

Now, for forty times in which he passes through an intersection , we want to know the number of times in which he would be stopped

In this case we only need to multiply the probability by the number of times in which he passes an intersection and that would be 2/5 * 40 = 16 times

ruth is 6 years old

step-by-step explanation:

6 + 24 = 30,   so 6/30 = .2  

if you do 1/5 it also equals .2, so that is the answer.

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for