The number 3 × 5 × 7 × 11 + a, where a is the odd number is: a) Always prime number b) Always even number c) Always odd number d) Composite number
The number 3 × 5 × 7 × 11 + a, where a is the odd number is: a) Always prime number b) Always even number c) Always odd number d) Composite number Correct Answer b & d
Concept used:
Prime number: It is the positive integer having only two factors, 1 and itself.
Even number: A number that is divisible by 2
Odd number: A number that is not divisible by 2
Composite number: The composite number is the positive integers which have more than two factors.
Calculation:
Our number is 3 × 5 × 7 × 11 + a
Taking a = 1, then
Number = 1155 + 1 = 1156
Taking a = 3, then
Number = 1155 + 3 = 1158
∴ The given number is a composite number and always even number.
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Feb 20, 2025