-5 -(-1) = -5+1= -4
and
-9 -(-5) = -9+5 = -4
we observe that the number are in AP
of the AP -
ist term = -1
common difference = -4
19th term = -1 + (19-1)(-4)= -1 -72 = -73
_________________________
the correct answer = B
OK, so this is assuming we are considering that the first three kids to solve ARE NOT in the first day.
So we have 3 kids and it doubles
Day 1 : 6
Day 2 : 12
Day 3 : 24
Day 4 : 48
Day 5 : 96
Day 6 : 192
Day 7: 384
So it should take 7 days or a week to solve all the problems.
The equation:
(3 * 2)^x = 384
AB is divided into 8 equal parts and point C is 1 part FROM A TO B, so the ratio is 1:7, with C being 1/7 of the way. The ratio is k, found by writing the numerator of the ratio (1) over the sum of the numerator and denominator (1+7). So our k value is 1/8. Now we need to find the rise and the run (slope) of the points A and B.

. That gives us a rise of -4 and a run of 12. The coordinates of C are found in this formula:
![C(x,y)=[ x_{1} +k(run), y_{1} +k(rise)]](https://tex.z-dn.net/?f=C%28x%2Cy%29%3D%5B%20x_%7B1%7D%20%2Bk%28run%29%2C%20y_%7B1%7D%20%2Bk%28rise%29%5D)
. Filling in accordingly, we have
![C(x,y)=[-3+ \frac{1}{8}(12),9+ \frac{1}{8}(-4)]](https://tex.z-dn.net/?f=C%28x%2Cy%29%3D%5B-3%2B%20%5Cfrac%7B1%7D%7B8%7D%2812%29%2C9%2B%20%5Cfrac%7B1%7D%7B8%7D%28-4%29%5D%20%20)
which simplifies a bit to

. Finding common denominators and doing the math gives us that the coordinates of point C are

. There you go!
Ceiling Function is the least integer that is greater than or equal to x.
Point R and point T have same x coordinate so their distance is by y axis.
Ty-Ry=2.4-1.3=1.1
So the distance between two points is 1.1