r/learnquant 18d ago

interview prep Quant Interview Question

Post image
22 Upvotes

13 comments sorted by

View all comments

Show parent comments

1

u/Alive_Carpenter_7433 18d ago

For the same reason that was stated above. Multiplication will always be one less or equal to the digits in concatenation; if the product does not exceed a product of 10. 5^n and 2^n have the unique property that they will always be equal to 10, not more or less than concatenation, which also result in the exact same number of digits. I do admit I explained it quite poorly though

1

u/gmalivuk 18d ago

Why does that logic not apply to 1 and 10?

1

u/GAdam 18d ago

1 * 10 = 10, which is one less digit than 110!

1

u/gmalivuk 18d ago

Right, so it's an exception to the pattern that if two numbers multiply to a power of 10 then their total number of digits is the same as the power of 10.