Which is the best definition of a phylogenetic tree?
2 answers:
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Answer:
a) price of an exercise book = #200
b) #400
Explanation:
Let x represent the price of the book
Let y represent the price of the exercise book
- According to this question, the price of the book is thrice that of an exercise book i.e. x = 3y
- Also, the question states that if a student spend #9600 on book and #8000 on exercise book, he has 56 items altogether. This means that to get how many books and exercise books he bought, we divide the price of book and exercise book he bought by the price of each book (x) and exercise book (y) respectively. Mathematically, this means:
- Student bought 9600/x books
- Student bought 8000/y exercise books
So, 9600/x books + 8000/y exercise books = 56 item
9600/x + 8000/y = 56
Since x = 3y
We can say;
9600/3y + 8000/y = 56
Find the L.C.M of 3y and y = 3y and solve using fraction method (see attachment).
9600 + 24000/3y = 56
33600/3y = 56
Cross multiply
33600 = 56 × 3y
33600 = 168y
Divide both sides by 168
33600/168 = 168y/168
200 = y
y = 200
Since, x = 3y
x = 3 × 200
x = 600
Therefore, the price of book (x) and exercise book (y) are #600 and #200 respectively.
b) The difference between the price of a book and an exercise book i.e. x - y
= #600 - #200
= #400
