Answer:
Step-by-step explanation:
Remark
The two trains are travelling towards each other. That means that their total distance = 912 km. Neither one has gone that distance by itself. The effect this has on the question is that you add the two rates multiplied by time.
Givens
r1 = x
r2 = x + 12
t = 3 hours
d = 912 km
Equation
d = r * t
r1 * t + r2 * t = 912
Solution
3x + 3*(x + 12) = 912 Remove the brackets
3x + 3x + 36 = 912 Combine like terms
6x + 36 = 912 Subtract 36 from both sides
<u> -36 -36</u>
6x = 876 Divide both sides by 6
6x/6 = 876/6
x = 146 km/h
Answer
Slow train = 146 km/hr
Fast train = 146 + 12 = 158 km/hr
Answer:
$3/book
Step-by-step explanation:
cost per book means divide the price of all the books by the number of books
$15/(5 books) = $3/book
60% of the total (30) can swim
60% of 30 = (60/100)*30 = 0.60*30 = 18
So 18 children can swim
This means 30-18 = 12 cannot swim
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An alternative is to do it this way:
We know 60% can swim so that means 40% cannot swim.
Notice how 100% - 60% = 40%
Or in other words, the 60% and 40% add to 100%. This is because we have two choices: either the person can swim or cannot swim
Since 40% cannot swim, this means
40% of 30 = (40/100)*30 = 0.40*30 = 12
and we get the same result as before
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Final Answer: 12
Answer:
7/2
Step-by-step explanation:
The slope of the line is given by
m = (y2-y1)/(x2-x1)
= (-1-6)/(9-11)
= -7/ -2
= 7/2
m∠3 = 180 - m∠8 = 180 - 123 = 57
m∠1 = m∠3 = 57°
