One eighth of a number is ten less than one third of the number. Find the number.

X/8 - 10 = x/3

bring the values with the variable on one side

x/3 - x/8 = 10

find a common denominator and subtract these fractions

8x/24 - 3x/24 = - 10

now subtract fractions

8x - 3x = 5x

5x/24 = - 10

multiply both sides by 24

5x = - 240

divide both sides by 5

x = - 48

the number is - 48