C. 42.39 times 0.1 is 4.239. 42.39-4.239= 38.151 which rounds to 38.15
Let's define variables:
s = original speed
s + 12 = faster speed
The time for the half of the route is:
60 / s
The time for the second half of the route is:
60 / (s + 12)
The equation for the time of the trip is:
60 / s + 60 / (s + 12) + 1/6 = 120 / s
Where,
1/6: held up for 10 minutes (in hours).
Rewriting the equation we have:
6s (60) + s (s + 12) = 60 * 6 (s + 12)
360s + s ^ 2 + 12s = 360s + 4320
s ^ 2 + 12s = 4320
s ^ 2 + 12s - 4320 = 0
We factor the equation:
(s + 72) (s-60) = 0
We take the positive root so that the problem makes physical sense.
s = 60 Km / h
Answer:
The original speed of the train before it was held up is:
s = 60 Km / h
Here it is given that the triangles ABP and DCR are similars, therefore we use the ratio rule which states that
corresponding sides of similar triangles are in same proprtion .

that gives
7/10 = BP/11
7*11=10BP
BP=7.7
Again using the ratio rule

7/10 = AP/6
42 = 10AP
AP = 4.2
Perimeter= AB+BP+AP = 7+7.7+4.2 = 18.9
Correct option is A.
To find the area of the rectangle, do A=lw which is 4x13=52. to find the area of the triangle, first find the height. this is 13-6=7. now do A=bh/2 which is (5x7)/2=17.5. 17.5+52=69.5 which is your answer. DONT OPEN ANY LINKS ON HERE, ITS A VIRUS
To arrange the slopes we need to take their absolute values.
1. U<span>ndefined slope means a vertical line, so it is going to be steepest.
2.|4/3| = 4/3
3.|-3/2| = 3/2
4. 0 means horizontal line.
</span>From flattest to steepest: 0, -3/2, 4/3, undefined.