Answer:
100degrees
Step-by-step explanation:
Find the diagram attached
From the diagram
<PQT =<TRS = 40
Since the triangle STR is isosceles, here,
<TSR =<TRS = 40
Also the sum of angle in a triangle is 189, hence:
Arc SR+<TSR +<TRS = 18₩
ArcSR +40+40=180
ArcSR +80=180
ArcSR = 180-80
ArcSR = 100degrees
Hence the measure of SR is 100degrees
Answer:
(a) 120 choices
(b) 110 choices
Step-by-step explanation:
The number of ways in which we can select k element from a group n elements is given by:
So, the number of ways in which a student can select the 7 questions from the 10 questions is calculated as:
Then each student have 120 possible choices.
On the other hand, if a student must answer at least 3 of the first 5 questions, we have the following cases:
1. A student select 3 questions from the first 5 questions and 4 questions from the last 5 questions. It means that the number of choices is given by:
2. A student select 4 questions from the first 5 questions and 3 questions from the last 5 questions. It means that the number of choices is given by:
3. A student select 5 questions from the first 5 questions and 2 questions from the last 5 questions. It means that the number of choices is given by:
So, if a student must answer at least 3 of the first 5 questions, he/she have 110 choices. It is calculated as:
50 + 50 + 10 = 110
