1. G

    Please answer this two doubts from Cost price problem.

    Rohan purchased a bike for Rs 54000. He sold it at a loss of 8 percent. With that money he again purchased another bike and sold it at a profit of 10 percent. What is his overall loss\profit? Loss% = 8% = 8/100; Initial Price : Final Price = 100 : 92 Profit% = 10% = 1/10; Initial Price ...
  2. B

    a simple system with an impossible answer...

    first post here... currently an applied math student attending Stonybrook university. The question seems so simple. But I am unable to find an answer. jack can do 3 chemistry problems and 6 math problems an hour. Jill can do 4 chemistry problems and 7 math problems an hour. How long must...
  3. G

    Just answer this doubts from S.I problem.

    If a sum of money amounts to Rs 12900 and Rs 14250 at the end of 4th and 5th year respectively at a certain rate of S.I , then the rate of interest is: 4 yrs ----- 12900 5 yrs ----- 14250 → 1 yrs ------ 1350. → 1350 * 4 = 5400. 12900 - 5400 = 7500 R = (1350/7500) * 100 = 18% I didn't...
  4. H

    Algebra what is the actual answer ?

    $$(a-b)^2=a^2-b^2$$ Which values of a and b show that this is not true?
  5. H

    A simple answer

    Am I allowed to make a new thread in maths where I believe I have already solved the answer to the question but seek confirmation and things I can add to the solving step?
  6. Y

    help: could not answer

    1. Which of these rectangular prisms has a base area of 40cm² and a volume of 160cm³? A. Height = 2cm, base length = 10cm, base width = 4cm B. Height = 4cm, base length = 4cm, base width = 4cm C. Height = 4cm, base length = 10cm, base width = 4cm D. Height = 10cm, base...
  7. C

    How is this answer possible?

    Dear My Math Forum: A ball of clay falls to the ground from a height of 15 meters. It is in contact with the ground for 0.020 seconds before coming to rest. What is the average acceleration of the clay during the time it is in contact with the ground? The correct answer to this...
  8. H

    Can you help me answer following python related questions?

    In Python, what is returned when evaluating [n for n in range(10) if n % 2]? In Python, what kind of error is returned by the following code? (e.g. NameError, ValueError, IOError, etc.) def my_func(n1, n2): return n1 + n2 my_func(1, 2, 3) What is returned by datetime(1970, 1...
  9. H

    Can you help me answer following mathematical questions?

    Let f(w) = 2w^3 - 5. What is f(4)? Let f(w) = 2w^3 - 5. Let z = 2. What is f(z)? Let g(x) = cos(x/2) - 3x. Let f(x) = 2x + 5. What is g(f(x))? Let f(x) = tan(x) - 2/x. Let g(x) = x^2 + 8. What is f(x)*g(y)? What is the derivative of x^2 - x + 3 at the point x = 5? What is the...
  10. P

    Feedback for an answer involving Span, Dimension and Linear Independence

    Hi guys, I have worked out an answer to the following question, but it's stretching my understanding of Linear Algebra to the limit, so… if anybody could have a look at it, and just tell me whether my reasoning is sound, it would be a great help... Let v_1,…,v_k,u,w be vectors in the...
  11. G

    Why first method answer didn't match second method?

    On a circular track of length 100m. A and B start running clockwise from the same point with speeds of 5m/sec and 7m/sec respectively. After how much time will they meet for the first time while running? First method: Track = 100m → SA/SB = 5/7 A does 5 rounds B does 7 rounds Difference...
  12. A

    What is the answer ?

  13. G

    Why 4:7 is not the answer?

    The contents of two vessels containing water and milk in the ratio 3:5 and 7:8 are mixed in the ratio 4:7. What would be the ratio of water and milk in the final mixture? Please don't post the final answer. My doubt is: Why 4:7 is not considered as ratio of water and milk in the final mixture?
  14. L

    Equations solvable only by directly providing the answer

    Are there equations with solutions, but totally unsolvable mathematically unless by substituting simple variables with given complex answers?
  15. G

    How to answer this one?

    A, S, O, D, F and T are the six members of a family. Among them there are three men and three women, and two married couples. We also know that: O is the son of S. T is the daughter of D F is the grandson of A D is the mother of a girl and a boy S is not the father of O. Who is the father...
  16. D

    Why is choice 3 the answer?

    (ex) Which of the following statements is true? (1) If P=Q, then P^n=Q^n where n is any integer (2) If P^n=Q^n, then P=Q where n is any integer (3) If P=Q, then P^n=Q^n where n is any positive integer (4) If P^n=Q^n, then P=Q where n is any positive integer my attempt If I let P and...
  17. D

    Is the key answer wrong?

    (ex) What is the approximate combined loudness in decibels of a garbage disposal and a washing machine, each with a sound level of 80 decibels? my attempt I use the formula. D = 10*log(I1/I2) where D represents the loudness of sound, I1 the intensity of source 1 and I2 the intensity of...
  18. D

    Wrong Answer for Correct Procedure?

    Here is a problem: Solve: (x^2 - 4) = x^2 - 10x + 16 Procedure 1: factor both sides for (x+2)(x-2) = (x-8 )(x-2) divide out common factors (x+2) = (x -8 ) simplify 0 = -10 which is obviously wrong. Procedure 2: subtract all values on...
  19. G

    Solve. Answer only the positive solution.

    Unless this is too hard to explain for me here I just need steps for where to go from when I get the 2.56E-6 in order to get it to a fraction. Thanks for any reply even if I can't have a shown process.
  20. M

    Maths question. Please answer it is driving me crazy

    Ed has a very mixed DVD collection: of his 100 DVDs: ... 70 are DVD5 and 30 are DVD9 ..... 80 are region 2, 15 are region 1, and 5 are region 4...