Red and grey bricks were used to build a decorative wall. there were 140 bricks used in all. how many red bricks were used?

If your using variables, it could be with greater than or equal to signs involved such as:                                                                                                                 150 ≤ r                                                                                                                   The variable "r" standing for the number of red bricks     :) hope this is what you were looking for