Question

Lucas is learning the number series problem in his math class.

X, 4, XV, 16, XX, 64, XXV, 256, ___ , ___

Which two numbers should Lucas fill in to complete the series?

• A. VXX, 1024
• B. XVV, 1024
• C. XVX, 1024
• D. XXX, 1024

Answer 1

The correct option is D XXX, 1024

The given series is an alternating addition and multiplication series.

The Roman number series is: X, XV, XX, XXV
The Arabic series is: 4, 16, 64, 256

In the Roman numeral pattern, each number is increasing by 5.

In the Roman series:

• X + 5 = XV
• XV + 5 = XX
• XX + 5 = XXV
• XXV + 5 = XXX

In the Arabic numeral pattern, each number is being multiplied by 4.

• $4\times 4=16$
• $16\times 4=64$
• $64\times 4=256$
• $256\times 4=1024$

So, the next Roman and Arabic numbers in the series are XXX and 1024, respectively.