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.
If the last two digits of the number are divisible by four
60x20=1200
1200/300=4
4x1/2=4/2=2 pounds of grass seed
This is very easy question write all given and common