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If Jill’s age is increased by Mark’s age, the result is 2 times Jill’s age 5 years ago. If Mark is now M years old, what is Jill’s present age in terms of M? A. M + 5 B. M + 10 C. 2M – 10 D. 2M – 5 E. 2M + 5 Answer: B (Highlight the answer)

Thanks so much. It's much clear now.

The letters of the word PROMISE have to be arranged so that no two vowels come together. Find the number of arrangements. I don't know the solution and look for help. Thank you.

Jennifer and Alice are 4 miles apart. If Jennifer starts walking toward Alice at 3 miles per hour and at the same time Alice starts walking toward Jennifer at 2 miles per hour, how much time will pass before they meet? (A) 20 minutes (B) 28 minutes © 43 minutes (D) 48 minutes (E) 60 minutes Thank you.

If a and b are positive integers such that the greatest common factor of a2b2 and ab3 is 45, then which of the following could b equal? A. 3 B. 5 C. 9 D. 15 E. 45 I am not sure the answer. Please help.

You rock, pemdas. Cool. Thanks a lot.

A person covers equal distances with three different speeds which are integers in m/min. The sum of three speeds is 14 m/min. His average speed for the whole journey is 210/59 m/min. What was his lowest speed in m/min? (A) 2 (B) 3 © 1.5 (D) 2.5 (E) 7 I know CDE are not the answer but I am not sure what the correct answer is. In my opinion, 2 and 3 will work. Since 2 is smaller than 3, the answer is (A) 2 ???

X1 = 3 X2 - X1 = 2 = 2^1 X2 = 5 X3 - X2 = 4 = 2^2 X3 = 9 X4 - X3 = 8 = 2^3 X4 = 17 We can clearly see the pattern of difference. Xn+1 - Xn = 2^n So, X20 - X19 = 2^19

Prime number is its divisor is either 1 or itself. 15 2.5 Since we want 7p + 2, we need to make the middle p to 7p + 2 multiply the inequality by 7 then plus 2 33.3 35.3 ACE is outside of the inequality. 65 is not a prime number. The answer is B, 79.:)

Since there's only one standard deviation for a normal curve, we can use z score to solve this problem. From the question, we know two probabilities for 56 and 92. For scores For scores > 92, the probability = 80/500 = 0.16 The z score for the upper tail with an area of 0.16 is 0.9945 The z score for the lower tail with an area of 0.02 is -2.0537 The formula for z = (score - mean score) / standard deviation Let's consider two cases here, mean is 87 and 80 Case1: Mean=80 (92-80) / standard deviation = 0.9945 (92-80) / standard deviation = 0.9945, standard deviation = 12.06, (56-80) / standard deviation = -2.0537, standard deviation = 11.68, Round to the integer. Both are 12 so the standard deviation is 12. Case2: Mean=87 (92-87) / standard deviation = 0.9945, standard deviation = 5.027652 (56-87) / standard deviation = -2.0537, standard deviation = 15.09471 Those two deviations are way different. From those two numbers we also know that mean has to be smaller than 87 in order to make standard deviation to be very close. The answer is A. This is my explanation and hope it makes sense to you.