The tickets in a box are numbered from 1 to 15 inclusive. if a ticket is drawn at random and replaced and then a second is drawn at random, what is the probability that the sum of their numbers is even?
a. 49/225
b. 1/2
c. 113/225
i think it is c but i don't

We know that two odd numbers make an even number and two even numbers make another even number. So out of the first choice you have a 7/15 chance of getting it even and an 8/15 chance of getting it odd. 

If you get the first one even, then the second one MUST also be even so you multiply 7/15 with itself. 

If you get the first one odd, then the second one MUST also be odd so you multiply 8/15 with itself as well. 

You should have: 

(7/15) x (7/15) 

and 

(8/15) x (8/15) 

By multiplying the top portions with each other and the bottom portions with each other you get: 

49/225 and 64/225 respectively. 

Add both fractions together to get your answer. 

Your answer should be (64+49)/225 = 113/225 

Your answer is 113/225. 

Well, it seams as if you were correct. The answer is c. 113/225. Hope this helped!

c. 113/225

The formula used will be:

tan 42° = y/115

Step-by-step explanation:

Lets simplify the the question.

We have a boat which is situated at 115 meters away from a light house. It forms the base of the right angled triangle.

We need to find the distance from the bottom of the light house to the top of the light house. This distance is the height of the lighthouse, which forms the perpendicular side of the right angled triangle.

The distance between boat and top of the lighthouse is unknown, it forms the hypotenuse.

The angle of elevation, which is the angle between base and hypotenuse, is given as 42°.

The right angled formed is shown below.

We know that

tanθ = Perpendicular / Base

tan42 = height / 115

If height= y

tan 42° = y/115

Solve for y.

y = 103.55 meters