Carcass wrote:
The popular notion that a tree’s age can be determined by counting the number of internal rings in its trunk is generally true. However, to help regulate the internal temperature of the tree, the outermost layers of wood of the Brazilian ash often peel away when the temperature exceeds 95
degrees Fahrenheit, leaving the tree with fewer rings than it would otherwise have. So only if the temperature in the Brazilian ash’s environment never exceeds 95 degrees Fahrenheit will its rings be a reliable measure of the tree’s age.
Which of the following is an assumption on which the argument above depends?
(A) The growth of new rings in a tree is not a function of levels of precipitation.
(B) Only the Brazilian ash loses rings because of excessive heat.
(C) Only one day of temperatures above 95 degrees Fahrenheit is needed to cause the Brazilian ash to lose one ring.
(D) The internal rings of all trees are of uniform thickness.
(E) The number of rings that will be lost when the temperature exceeds 95 degrees Fahrenheit is not predictable.
kudos for R.A.E.
Hi Shefalisahu,
finally the question boils down to Only if X then Y....
what does this construction tells us That X is a must for Y..
here we have
only if the temperature in the Brazilian ash’s environment never exceeds 95 degrees Fahrenheit will its rings be a reliable measure of the tree’s age.
X is the temperature in the Brazilian ash’s environment never exceeds 95 degrees Fahrenheit
Y is its rings be a reliable measure of the tree’s age.
so X is a must for Y. therefore if X does not happen that is
the temperature exceeds 95 degrees F, the tree's age cannot be determined through the rings.
Choice E tells us that
The number of rings that will be lost when the temperature exceeds 95 degrees Fahrenheit is not predictable., and thus it fills the gap by telling us that there is noway to calculate the number of rings shed due to this excessive heat. so the Temp has to remain below the 95 degree F.