recall your d = rt, distance = rate * time.
let's say we have two trains, A and B, A is going at 85 mph and B at 65 mph.
they are 210 miles apart and moving toward each other, at some point they will meet, when that happens, the faster train A has covered say d miles, and the slower B has covered then the slack from 210 and d, namely 210 - d.
When both trains meet, A has covered more miles than B because A is faster, however the time both have been moving, is the same, say t hours.
![\bf \begin{array}{lcccl} &\stackrel{miles}{distance}&\stackrel{mph}{rate}&\stackrel{hours}{time}\\ \cline{2-4}&\\ \textit{Train A}&d&85&t\\ \textit{Train B}&210-d&65&t \end{array}\\\\ \dotfill\\\\ \begin{cases} \boxed{d}=85t\\ 210-d=65t\\[-0.5em] \hrulefill\\ 210-\boxed{85t}=65t \end{cases} \\\\\\ 210=150t\implies \cfrac{210}{150}=t\implies \cfrac{7}{5}=t\implies \stackrel{\textit{one hour and 24 minutes}}{1\frac{2}{5}=t}](https://tex.z-dn.net/?f=%20%5Cbf%20%5Cbegin%7Barray%7D%7Blcccl%7D%20%26%5Cstackrel%7Bmiles%7D%7Bdistance%7D%26%5Cstackrel%7Bmph%7D%7Brate%7D%26%5Cstackrel%7Bhours%7D%7Btime%7D%5C%5C%20%5Ccline%7B2-4%7D%26%5C%5C%20%5Ctextit%7BTrain%20A%7D%26d%2685%26t%5C%5C%20%5Ctextit%7BTrain%20B%7D%26210-d%2665%26t%20%5Cend%7Barray%7D%5C%5C%5C%5C%20%5Cdotfill%5C%5C%5C%5C%20%5Cbegin%7Bcases%7D%20%5Cboxed%7Bd%7D%3D85t%5C%5C%20210-d%3D65t%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20210-%5Cboxed%7B85t%7D%3D65t%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5C%5C%20210%3D150t%5Cimplies%20%5Ccfrac%7B210%7D%7B150%7D%3Dt%5Cimplies%20%5Ccfrac%7B7%7D%7B5%7D%3Dt%5Cimplies%20%5Cstackrel%7B%5Ctextit%7Bone%20hour%20and%2024%20minutes%7D%7D%7B1%5Cfrac%7B2%7D%7B5%7D%3Dt%7D%20)
The length of BC is 4.674 m
<u>Explanation:</u>
Given:
Angle A = angle B = 90°
AD = 2.1 m
AB = 1.9 m
CD= 3.2 m
An image is inserted for the reference
According to the figure,
a is the base
b is the height
c is the hypotenuse
Using pythagoras theorm:
a² + b² = c²
a² + (1.9)² = (3.2)²
a² + 3.61 = 10.24
a² = 6.63
a = 2.574
BC = 2.1 + 2.574
BC = 4.674m
Therefore, the length of BC is 4.674 m
14/20=0.7 or 70% are soft-centred. If we take two candies we have three possibilities associated with probabilities:
Both soft-centred: 0.7²=0.49 or 49%
Both hard-centred: 0.3²=0.09 or 9%
One of each: 2×0.3×0.7=0.42 or 42%. 49+9+42=100%. So these are all the possible outcomes.
The values of angles are 140 and 20
• In plane geometry, a figure which is formed by joining of two lines that share a common point is called as the angle. The two lines or rays are called as the sides of the angle and the common point is called the vertex.
• In geometry there are types of angles such as complementary angles, supplementary angles, acute angle, obtuse angles. Complementary angles are the angles whose sum is equal to 90. Supplementary angles are the angles whose sum is equal to 180.
According to the question
We are given that one angle is -7x and the other angle is -2x
Using formula of supplementary angles
-7x + (-2x) = 180
-7x -2x = 180
-9x = 180
-x = 20
x = -20
The value of x is -20
The value of angle – 7x = -7(-20) = 140
The value of angle -2x = -2(-20) = 40
Learn more about angles here
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