List of top Questions asked in CBSE Class X

Explain why \(7 × 11 × 13 + 13\) and  \(7 × 6 × 5 × 4 × 3 × 2 × 1 + 5\) are composite numbers.

Check whether \(6n\) can end with the digit \(0\) for any natural number \(n\).

Given that HCF \((306, 657) = 9\) , find LCM \((306, 657)\).

Find the LCM and HCF of the following integers by applying the prime factorisation method. 

1. \(12, 15\) and 
2.  \(17, 23\) and 
3. \(8, 9\) and \(25\)

Find the LCM and HCF of the following pairs of integers and verify that LCM × HCF = product of the two numbers.

1. \(26\) and \(91\)
2. \(510\) \(\)and \(92\)
3. \(336\) and \(54\)

Express each number as a product of its prime factors: 

1. \(140\) 
2. \(156\) 
3. \(3825\) 
4. \(5005\) 
5. \(7429\)