Answer: C. 625 and 81
Step-by-step explanation: A relatively prime pair is a pair in which in both numbers given, the only number that can go into each number is one. In 112 and 36, we know 2 can evenly go into each number because they both end in a positive number (112/2 is 56 and 36/2 is 18.) This means A is incorrect. As for B, 11 can evenly go into each number, leaving you with 25 and 7. B is incorrect. And then there's D. 5 can go into each number giving you 160 and 19. D is incorrect.
C is correct because the only numbers that can go evenly into 81 is 1, 3, 9, 27, and 81. None of these numbers, except one can go into 625 also.
In 2005 there were 9million bicycles in Beijing
Answer:

Step-by-step explanation:
STEP 1:
2/3 + 7/10 = ?
The fractions have unlike denominators. First, find the Least Common Denominator and rewrite the fractions with the common denominator.
LCD(2/3, 7/10) = 30
Multiply both the numerator and denominator of each fraction by the number that makes its denominator equal the LCD. This is basically multiplying each fraction by 1.
*
+
= ?
Complete the multiplication and the equation becomes

The two fractions now have like denominators so you can add the numerators.
Then:

This fraction cannot be reduced.
The fraction 41/30
is the same as
41 divided by 30
Convert to a mixed number using
long division for 41 ÷ 30 = 1R11, so
41/30 = 1 11/30
Therefore:
2/3+7/10= 1 11/30
STEP 2:
41/30 + -2/3
The fractions have unlike denominators. First, find the Least Common Denominator and rewrite the fractions with the common denominator.
LCD(41/30, -2/3) = 30
Multiply both the numerator and denominator of each fraction by the number that makes its denominator equal the LCD. This is basically multiplying each fraction by 1.

The two fractions now have like denominators so you can add the numerators.
Then:

This fraction can be reduced by dividing both the numerator and denominator by the Greatest Common Factor of 21 and 30 using
GCF(21,30) = 3

Therefore:
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