Which of the following is a pair of co-primes?
25 and 36
Two numbers are co-prime if their highest common factor (HCF) is 1.
\(25 = 5^2\) and \(36 = 2^2 \times 3^2\); they share no common prime factor, so \(\text{HCF}(25,36) = 1\).
\(44 = 2^2 \times 11\) and \(99 = 3^2 \times 11\) share the factor 11, so their HCF is 11, not co-prime.
\(27 = 3^3\) and \(36 = 2^2 \times 3^2\) share the factor 3, so they are not co-prime.
\(42 = 2 \times 3 \times 7\) and \(56 = 2^3 \times 7\) share factors 2 and 7, so they are not co-prime.
Hence, 25 and 36 form a pair of co-primes.
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Important Questions from LCM and HCF
The HCF and LCM of two numbers are 12 and 72, respectively. If the ratio of the two numbers is 2 ∶ 3, then the larger of the two numbers is:
Find the greatest number that will divide 43, 91 and 183 so as to leave the same remainder in each case.
Joseph visits the club on every 5 th day, Harsh visits on every 24 th day, while Sumit visits on every 9 th day. If all three of them met at the club on a Sunday, then on which day will all three of them meet again?
What is the least number which when divided by 12,20 and 24 leaves in each case a remainder of 8?
Which of the following is a pair of co-primes?
