# A short Riley Riddle that only goes one way

My prefix is not a dub

My infix is a common base

My suffix is a quingenti sub

My whole is a common replace

What am I?

My prefix is not a dub

L for lose - dub is a slang abbreviation for the letter W (double-u) usually for a win.

My infix is a common base

$$e$$ is the base of the natural logarithm.

My suffix is a quingenti sub

D - 500 in Roman numerals.

My whole is a common replace

LED - light-emitting diode, replacing other light bulbs. Diodes only let electricity flow in one direction.

• That was pretty quick, congrats! Feb 21 '20 at 7:50

Could you be

PROTEND?

My prefix is not a dub

PRO. One meaning of "dub" is "an inexperienced or unskilful person", and a pro would be the opposite.

My infix is a common base

TEN, a common base for human number systems.

My suffix is a quingenti sub

D, the Roman numeral for 500.

My whole is a common replace

PROTEND seems like a typo for the commoner word PORTEND.

Title:

PROTEND means to extend or stretch forth (in one direction).

• Nice answer! Unfortunately not the one I was looking for, although you got one of the fixes right ;) Feb 21 '20 at 7:52