Sven01

I struggle with the following equation that hast to be solved for n: 9^7+9^7+9^7 = 27^n+1 I tried to factor the numbers, but nevertheless I didn't get the right result. 3(9^7)= (3*9)^n+1 3(3^7*3^7)= (3*3*3)^n+1 3^15=3^3n+3 15=3n+3 n=4 But this solution is wrong! Why? Thanks in advance.

Thank you canadian phd. But I think that there is a little mistake. 36 km equals 36000 meter and therefore the train passes 10 meters per second. Thus the train has a length of 400 - 2 = 398 meters. Right? Greets Sven

I struggle with the following speed problem. A train traveling at 72 km/h passes a man on a bicycle traveling at 36 km/h completely in 40 seconds. If the length of the bicycle is 2 meters, what is the length of the train? I have no idea how to attack this problem. Perhaps somebody can help me!

Thank you very much!! Now, I've got it!;-) Just to answer your question, why I assumed that 3 people study accounting and marketing: I just have choosen three preople out of the nine who study TWO of the subjects, as we have 3 subjects and 9 people. Therefore I just divided 9 by the three subjects to make it easier for calculation. At the end, you are completely right it has to end up with 12 people, that have to be substracted (keeping in mind the one who studies all three subjects!). Last remark: I have also found my mistake when calculating the "40".;-)

You have written 21 accounting, but it is given, that 22 are studying accounting. Therefore why do I have to take 21 for accounting? And in addition if I take the sum of 22 (21) + 14 +13, I will get 51 (50) and if i subtract 9, I will receive 42 (41) but not 39. So I cannot understand your explanation. Perhaps you can explain it again. This would be nice. One remark to my solution. I subtracted 4 according to the formula as three people study for example both accounting and marketing and in addition the one person that studies all three subjects. I have tried to figure this out according to a Venn Diagram.

One evening at a party with 50 people it was discovered that 22 people study accounting, 15 people study marketing and 14 people study economics. If there are 9 people that study exactly two subjects and 1 person studies all three, how many people study none of the topics? I tried to solve this problem by using the following formula: n(A U B U C) = n(A) + n(B) + n© – n(A ñ B) – n(B ñ C) – n(C ñ A) + n(A ñ B ñ C) Therefore I got: 22+14+15-4-4-4+1=36 Substracting this number from 50 yields 14. But the result has to be 10. Perhaps somebody can tell me what I'm doing wrong. Thanks Sven

Hey guys, Thank you for your solutions. Meanwhile I know, that 10000 is the right answer choice. I think the explanations of solmon and bellcurve are precise and right. Thank you for your help. Greets Sven

Perhaps, somebody can help me to solve the following task: On a certain scale of intensity, each increment of 10 in magnitude represents a tenfold increase in intensity. On this scale, an intensity corresponding to a magnitude of 165 is how many times an intensity corresponding to a magnitude of 125? (A) 40; (B) 100; © 400; (D) 1000; (E) 10000 Thank you for your help in advance!

Thank you very much. Your answer is very helpful. Now I 've got the point. It's not as hard as I thought.;-)

Thank you for the answer, it's logical, but I still do not know how to get "k". Perhaps you could go into more detail. Thanks.

Following equation: If x+y/xy = 1, then Y = The right answer should be: x/ x-1 But I didn't get the right way to solve for Y. I need a hint. Thanks

I need help for the following problem: A necklace is made by stringing N individual beads together in the repeating pattern red bead, green bead, white bead, blue bead, and yellow bead. If the necklace design begins with a red bead and ends with a white bead, then N could equal (A) 16 (B) 32 © 41 (D) 54 (E) 68 Perhaps somebody has an idea. Thanks in davance.