Answer:
The average number of customers per day during the sale was 150.
Step-by-step explanation:
This question can be solved using a rule of three.
Before the sale, the average number of customers per day was 120, which is 100% = 1.
Now, there are x customers, and since it is an increase of 25%, it is 100+25 = 125% = 1.25. So
120 - 1
x - 1.25
x = 1.25*120 = 150
The average number of customers per day during the sale was 150.
The probability of drawing a white marble =

∴ the probability of drawing a white marble = ³/₁₄
Heron's formula is named after Hero of Alexendria, a Greek Engineer and Mathematician in 10 - 70 AD. You can use this formula to find the area of a triangle using the 3 side lengths.
Therefore, you do not have to rely on the formula for area that uses base and height. The picture below illustrates the general fro mu la where S represents the semi-perimeter of the triangle ,