X=4a+3b, If a is a two digit cube number and b is a two digit square number then what is the lowest possible value for X?

In order to find the lowest value for X we first need to find the lowest possible value for a and b.

Let us start off with a:

If a is the lowest possible cube number we can start by checking the first couple of cube numbers and we get:

- 1^3 = 1

  • 2^3 = 8
  • 3^3 = 27

Hence, the lowest possible two digit cube number we can get is 27, so a=27. Now let us check for b, what is the lowest possible two digit square number:

- 1^2 = 1

  • 2^2 = 4
  • 3^2 = 9
  • 4^2 = 16

Hence, the lowest possible square number we can get is 16, so b=16.

Now the math is easy, we just plug our values for a and b into the equation to find the answer:

X = 427 + 316 = 108 + 48 = 156

So the answer is 16.
 

SI
Answered by Silje I. Maths tutor

4218 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Max invests £2000 and gets 2.5% compound interest per year. Jade invests £1600 and gets 3.5% compound interest per year. Work out who will get the most interest by the end of 3 years.


Factorise f(x) = x^2+4x+4 and sketch the curve, identifying the roots and minimum point of f(x).


How do I expand and simplify linear equations?


Solve the following equation by factorisation: x^2 - 2x -15 = 0


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning