Question

PLZ HELP!! 10 PTS!!

Given a grid with 15 sections, determine how many sections in the grid need to be shaded so the probability of a point chosen at random in the shaded area is exactly 0.8. Explain your reasoning.

Answer 1

The number of squares that are shaded divided by 15 must equal 0.8, so the number of squares must be 0.8(15), which equals 12. The fraction 12/15 reduces to 4/5 which is equal to 8/10.

Answer 2

There are 15 sections
To make the probability of choosing a shaded section 0.8, 0.8 of the 15 sections must be shaded

0.8 of 15 is 12 (to calculate do 15 x 0.8)

Therefore there needs to be 12 shaded sections