Answer:
The list od prime number is a quadratic sequence, each time going up by n + 2. for example, 1, 4, 9, 16, 25. they are going up by 3, then + 2 and add 2 every step. The sequence is always going up by an odd number. a negative number take away a negative number always gives you a positive number, likewise, adding does too. Therefore, you can not get both of them to fit into the sequence of increasing odd numbers.
check the picture below.
so it has a base of 18x18 and a height of that much.
Let n = minutes since 12:00 pm when Malory catches up to Dori.
Dori travels
(50 steps/min)*(n minutes) = 50n steps
Malory begins walking at 12:20 pm, so she walks for (n - 20) minutes. She travels
(90 steps/min)*(n - 20 min) = 90n - 1800 steps
Equate the steps traveled by Dori and Malory.
90n - 1800 = 50n
40n = 1800
n = 45 min
The time corresponding to n = 45 min is 12:45 pm
Answer: 12:45 pm
