6a - 3a + 9a= 12a yes u must makesure that u must have to do the working ive alrdy wrote it up there so u cn just follow okay thanks
Answer:
(b) The probability is 0.375
(c) The probability is 0.750
Step-by-step explanation:
The probability is calculated as a division between the number of options that satisfy a condition and the total number of options.
For part (b), we have 8 cavities or options for obtain the part but we want to obtain the part from cavity 1, 2 or 3, so we have 3 options. Therefore, the probability is:

For part (c), We have 8 cavities or options for obtain the part and we want to obtain the part from any cavity except cavity 3 or 4, so we have 6 options. These options are cavity 1, cavity 2, cavity 5, cavity 6, cavity 7 and cavity 8. Then, the probability is:

P(the students she selects are both boys)=7/12×5/10=35/120=7/24
Answer:
4/10, 5/10, 6/10 are all fractions in between 3/10 and 9/10
Step-by-step explanation:
Seven hundred ten thousand and two hundred