Is a reflection of (-7,2) across the y-axis is at (7,-2)
1 answer:
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Answer :
<h3>Step-by-step explanation:
Given that a multiple-choice test contains 10 questions and there are 4 possible answers for each question.
∴ Answers=4 options for each question.
<h3>To find how many ways a student can answer the given questions on the test if the student answers every question :</h3>Solving this by product rule
Product rule :
<u>If one event can occur in m ways and a second event occur in n ways, the number of ways of two events can occur in sequence is then m.n</u>
From the given the event of choosing the answer of each question having 4 options is given by
The 1st event of picking the answer of the 1st question=4 ,
2nd event of picking the answer of the 2nd question=4 ,
3rd event of picking the answer of the 3rd question=4
,....,
10th event of picking the answer of the 10th question=4.
It can be written as by using the product rule
Answer:
15 years old
Step-by-step explanation:
Start by defining the variables that we are going to use throughout our working:
Let the current age of Wei Ling and Wei Xuan be L and X years old respectively.
Next, form equations using the given information.
<u>5 years </u><u>ago</u>
Wei Ling: (L -5) years old
Wei Xuan: (X -5) years old
Given that the ratio of Wei Ling's age to that of Wei Xuan's is 2: 5,
Cross multiply:
2(X -5)= 5(L -5)
Expand:
2X -10= 5L -25
2X= 5L -25 +10
2X= 5L -15 -----(1)
<u>9 years time</u>
Wei Ling: (L +9) years old
Wei Xuan: (X +9) years old
Given that the ratio of Wei Ling's age to that of Wei Xuan is 3: 4,
Cross multiply:
3(X +9)= 4(L +9)
Expand:
3X +27= 4L +36
3X= 4L +36 -27
3X= 4L +9 -----(2)
Let's solve using the elimination method.
(1) ×3:
6X= 15L -45 -----(3)
(2) ×2:
6X= 8L +18 -----(4)
(3) -(4):
6X -6X= 15L -45 -(8L +18)
0= 15L -45 -8L -18
0= 7L -63
7L= 63
L= 63 ÷7
L= 9
Substitute L= 9 into (1):
2X= 5(9) -15
2X= 45 -15
2X= 30
X= 30 ÷2
X= 15
Thus, Wei Xuan is 15 years old now.