feynman

The deduction is pretty simple. Option D says plague broke out in the 1100s. If the fourth copyist wrote about plague then it must have been done in the 1100s or later. This is the only option that supports the correlation of plague, the treatise and the 1100s. Hence this is the right answer. Its not pretty, but its the best choice.

E is the best choice among the alternatives listed. If you go by elimination, E seems to be the only logical answer. So the answer is that the workders have to be trained to acquire new skills as their old skills become obsolete. Option E effectively implies that the workers will be trained to meet their job requirements (new skills). Option A comes close, but is not quite as complete as option E. The other options are all off the track.

Note on Circular permutations ----------------------------- Many ppl find circular permutations confusing. So I'm adding a note which will probably clear up things as to why circular permutation is usually (n-1)!. Suppose you have to seat 10 people in a circle. Think of it this way. You first seat one person. Now we're left with 9 people for 9 places which is just like a linear permutation. This can be done in 9! ways. Extending this concept to n objects, we get circular permutation of n unlike objects = (n-1)!

Solution to 417 : You just have to calculate the LCM (Least common multiple) of the given numbers. Remember the way to calculater LCM that we learnt back in school ?? 2 | 2,3,4,5,6,7,8,9 ------------------ 3 | 1,3,2,5,3,7,4,9 ------------------ 2 | 1,1,2,5,1,7,4,3 ------------------ 1,1,1,5,1,7,2,3 So LCM = 2 * 3 * 2 * 1 * 1 * 1 * 5 * 1 * 7 * 2 * 3 = 2520 which is choice C.

Solution to 426 : During the first hour 25% of 280 displays are assembled, which is 70. During the 2nd hour, 40% of the displays remaining unassembled after the 1st hour are assembled, which is 40% * 75 * 280, which is 84 So total number of displays assembled so far = 70 + 84 = 154 Hence the total numbe rof displays unassembled after 2 hours = 280 - 154 = 126 which is choice C.

The noun that is in the limelight here is 'pattern' and not 'changes'. 'pattern' is singular and hence the correct verb form is 'indicates' and not 'indicate'.