The L.C.M. of two numbers is 210 and their H.C.F. is 3. If the first number is divided by 3, the quotient is 7 and the remainder is 0. The second number is:
30
Given that the first number divided by 3 gives quotient 7 with remainder 0, the first number is \(3\times 7 = 21\).
For any two numbers, product = LCM × HCF, i.e. \(a\times b = \text{LCM}\times\text{HCF}\).
Substitute: \(21\times b = 210\times 3 = 630\).
Solve: \(b = \dfrac{630}{21} = 30\).
Hence, the second number is 30.
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A and B are two prime numbers such that A > B and their LCM is 209. The value of A 2 - B is:
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