Question

The number of rooms on the ground floor of a building is 15 less than twice the
number of rooms on the first floor. If the first floor has x rooms, how many rooms does the
ground floor has? 2 marks

Answer 1

Step-by-step explanation:

Given

Number of rooms on the first floor =x

Twice the number of rooms on the first floor =2x

We know that the word 'less than' a number means 'subtracting' it from a number.

12 less than the number of rooms on the first floor =2x−12

∴ Number of rooms on the ground floor of a building =12 less than the number of rooms on the first floor

=2x−12