Which of the following pairs of numbers are co-prime?

(i) 12 and 35

(ii) 15 and 37

(iii) 27 and 32

(iv) 17 and 85

(v) 515 and 516

(vi) 215 and 415

Express each of the following numbers as the sum of two odd primes:

(i) 24

(ii) 36

(iii) 84

(iv) 98

Express each of the following numbers as the sum of three odd primes:

(i) 21

(ii) 35

(iii) 49

(iv) 63

Which of the following numbers are divisible by 5 or by 10:

(i) 3725

(ii) 48970

(iii) 56823

(iv) 760035

(v) 7893217

(vi) 4500010