Answer:
there are 70 possible choices for the four locations to apply the new ointment
Step-by-step explanation:
Since we have a total of 8 locations ( 4 to the new ointment and 4 to the control) , each one can be chosen and since the order of the locations that are chosen for the new ointment is not relevant , then we know that the number of choices is given by the number of combinations of 4 elements in 8
number of combinations = 8 possible locations to the first ointment * 7 possible locations to the second ( since the first one was already located) * 6 to the third * 5 locations for the fourth / number of times the same combination is repeated ( the same locations but in different positions) = 8*7*6*5 / (4 possible positions for the first ointment* 3 possible positions to the second ointment (since the first one was already located * 2 possible positions of the third * 1 possible position of the fourth)
therefore
number of combinations = 8*7*6*5/(4*3*2*1 ) = 8!/((8-4)!*4!) = 70 possible combinations
thus there are 70 possible choices for the four locations to apply the new ointment
The major axis of the eclipse is 12 units long
The given parameters can be represented as:


See attachment for illustration
To solve this question, we make use of the following theorem
The distance between a point and the foci sums up to the major axis
This translates to:


