The product of two rational numbers is always rational because (ac/bd) is the ratio of two integers, making it a rational number.
We need to prove that the product of two rational numbers is always rational. A rational number is a number that can be stated as the quotient or fraction of two integers : a numerator and a non-zero denominator.
Let us consider two rational numbers, a/b and c/d. The variables "a", "b", "c", and "d" all represent integers. The denominators "b" and "d" are non-zero. Let the product of these two rational numbers be represented by "P".
P = (a/b)×(c/d)
P = (a×c)/(b×d)
The numerator is again an integer. The denominator is also a non-zero integer. Hence, the product is a rational number.
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Answer: it will take 2.5 hours for both people to meet after person B leaves.
Step-by-step explanation:
The distance between the house of person A and his cousin's house is 234 miles.
At the point where they meet, they would have travelled 234 miles.
Person A travelled at an average speed of 44 miles per hour.
Let t represent the time spent by Person A in travelling from his house to the point where they meet.
Distance = speed × time
Distance covered by person A would be
44 × t = 44t
One and half hours later, person B leaves his house to visit person A, travelling at an average speed of 62 miles per hour. This means that total time spent by person B in travelling to the point where they meet is (t - 0.5) hours. Distance covered would be
62(t - 0.5) = 62t - 31
Since the total distance covered is 234 miles, then
44t + 62t - 31 = 234
106t = 234 + 31 = 265
t = 265/106 = 2.5 hours
Answer: Option C)1 over 15 minus 1 over x equals 1 over 20
Explanation:
Since, Micah can fill a box with books in 15 minutes.
Therefore, the work done by Micah in one minute= 1/15
Also, Sydney takes the books out puts them on a shelf.
And the times taken by Micah when Sydney is also taking the books outside from the self= 20 minutes
Therefore, the work done by Micah in one minute when Sydney taking books out of the box= 1/20
Let Sydney alone takes x minutes to take books outsides the shelf.
Then, work done by Sydney in one minute=1/x
Thus, the work done by Sydney( by taking books out of the box)= the work done by Micah - work done by Micah and Sydney simultaneously= 1/15-1/20
⇒1/x=1/15-1/20
⇒1/15-1/20=1/x
⇒1/15-1/x=1/20 is the required expression.
Therefore, Option C is correct.
Answer: $4.50 for 9 apples
Step-by-step explanation: To find out how much it is for 1 apple, we need to find the unit price of 1 apple which is the cost per apple.
Since we know that it costs $4 for 8 apples, to find the cost for 1 apple, we need to divide 8 into $4 or 4 divided by 8 which is 0.5 of 50 cents per apple.
Since we know that it costs 50 cents per apple, to find the cost for 9 apples, we will need to multiply .50 by 9.
(.50) (9) = 4.50
Therefore, it will cost $4.50 for 9 apples.
