word problem, totally lost!?

Question

If an animal had 60 teeth at age 5 and 48 teeth at age 12, how many teeth was it born with?

Is the answer 69, 70, 72, or 80?

Answer 1

Assume that the equation for losing teeth is linear. The linear equation (also known as the equation for a line) is the following:

y=m*x + b where

y = # of teeth left, x = the age
m = the slope, the rate that the animal loses its teeth
b = the initial amount of teeth in the animal

For the case where x = 5 (years), the linear equation becomes
60 = m*5 + b

for the case where x = 12 (years), the linear equation becomes
48 = m * 12 + b

You have two linear equations and two unknowns, m and b.

Solve for m and b.

m = - 12/7
b = 60 + 60/7 = 68.857. That rounds up to 69.

Answer 2

The answer is 69.

Let x be the change in the number of teeth and y be the change in the number of years.

Then dx / dy = 12 / 7, and the ratio of the change in the number of teeth from age 0 to age 5 is the same, assuming this is a linear function.

So we get this relationship:

(x - 60) / 5 = 12 /7.

Cross multiplying we get:

7x - 420 = 60 ---> 7x = 480.

Dividing through by 7 gets us x = 68.57, or approximately 69 teeth.

Answer 3

I think it is 69! Because if the animal lost 12 teeth in 7 yrs. 12 divided by 7= aprox. 1.7 so say 2! Then for the first 5 yrs. 2x5=10 but it is a little less than 2 so 69! I am just guessing but this is how I got my answer!

Answer 4

I would say 69
a rated change per year is 1.714
I got that by subtracting 48 from 60 which is 12
then the years difference which is 7
divided 12 by 7 which is 1.714285714
multiplied that times 5 which is the age of 0
and added it to 60 which would be 68.571428571
round it up and it would be 69

That would be and elementry answer if you need a better answer
I need to know what class you are in because if it is calculas you would need to use summation notation or create an algebraic expression and use limits

Answer 5

69

Answer 6

Well, it lost 12 teeth in 7 years. So, how many teeth would it have lost in 5 yrs?

Answer 7

69 is the correct answer

the animal lost 1.71 teeth per year 1.71= (60-48)/(12-5)

then back into the number of teeth from age five plus 1.71 for five years which equals (60+8.57=68.57)

hope that helps

Answer 8

Somehow I think there was some information left out, but, logically thinking, teeth naturally occur in sets of four. One (or more) of each kind on each side, top and bottom. The only answers divisible by four are 72 and 80, so is would have to be one of those.

Answer 9

70

Answer 10

70