Q7 · General Aptitude · MCQ · 2 marks
X is a 30 digit number starting with the digit 4 followed by the digit 7. Then the number will have:
- (A)90 digits
- (B)91 digits
- (C)92 digits
- (D)93 digits
Answer (official key): A
Solution
Since is a 30-digit number starting with 47, it satisfies approximately:
Cubing,
Now,
and
So lies between approximately:
and
A number in this range has 90 digits.
Therefore, the correct answer is Option A.
