گاما رو نصب کن!

{{ number }}
اعلان ها
اعلان جدیدی وجود ندارد!
کاربر جدید

جستجو

پربازدیدها: #{{ tag.title }}

جستجوهای پرتکرار

میتونی لایو بذاری!

Mary saves her digital images on her computer in three separate folders named ‘Family’, ‘Holiday’ and ‘Friends’. Her family folder contains 3 images, her holiday folder contains 4 images and her friends folder contains 8 images. All the images are different.

a) Find in how many ways she can arrange these 15 images in a row across her computer screen if she keeps the images from each folder together.

b) Find the number of different ways in which Mary can choose 6 of these images if there are 2 from each folder.

c) Find the number of different ways in which Mary can choose 6 of these images if there are at least 3 images from the friends folder and at least 1 image from each of the other two folders.

پاسخ تشریحی :
نمایش پاسخ

a) $3! \times 4! \times 8! \times 3!$

$ = 34{\text{ }}836{\text{ }}480{\text{ }}\left( {34{\text{ }}800{\text{ }}000} \right)$

b) ${}^3{C_2} \times {}^4{C_2} \times {}^8{C_2}$

$ = 504$

c) $Fr{\text{ }}Fa{\text{ }}H$

$3{\text{ }}\,\,1{\text{ }}\,\,2 = {}^8{C_3} \times {}^3{C_1} \times {}^4{C_2} = 1008$

$3{\text{ }}\,\,2{\text{ }}\,\,1 = {}^8{C_3} \times {}^3{C_2} \times {}^4{C_1} = 672$

$4{\text{ }}\,\,1{\text{ }}\,\,1 = {}^8{C_4} \times {}^3{C_1} \times {}^4{C_1} = 840$

total ways $ = 2520$

تحلیل ویدئویی تست

تحلیل ویدئویی برای این تست ثبت نشده است!