Solution
Given:In this question, we are given that,
• P is a two-digit number.
• P = 30a + b, where a and b are positive integers.
To find:• The remainder, when P is divided by 3.
Approach and Working:We know that P can be expressed in the form 30a + b.
• Hence, if P is divided by 3, we can actually divide 30a and b separately by 3, and then add the remainders to get the final answer.
• However, irrespective of the value of a, 30a will be always divisible by 3.
o Hence, if we get any remainder, that we will get when we will divide b by 3.
Therefore, we can conclude that, to determine the remainder when P is divided by 3, we need to know the value of b.
With this understanding, let’s now analyse the statements.
Analysing Statement 1As per the information given in statement 1, a = 3.
• However, this statement gives us no information about the value of b.
Hence, statement 1 is not sufficient to answer the question.
Analysing Statement 2As per the information given in statement 2, \(b^3 – 5b^2 – 14b = 0\)
Simplifying the given equation, we get,
• \(b (b^2 – 5b – 14) = 0\)
Or,\(b (b^2 – 7b + 2b – 14) = 0\)
Or, b [b (b – 7) + 2 (b – 7)] = 0
Or, b (b – 7) (b + 2) = 0
Hence, b = -2 or 0 or 7
But we already know that b is positive.
• Therefore, we can say b = 7.
As we can find the unique value of b from statement 2, we can conclude that statement 2 is sufficient to answer the question.
Combining Both StatementsSince we got an answer from the second statement individually, we don’t need to combine the statements.
Hence, the correct answer is option B.
Answer: B