x has two values 4 and 5 by factorization or using the general formula
Solution :
It is given that four different prizes were awarded. So,
a). 4 ways for person 47 to win a prize
99 ways to give out the 2nd prize
98 ways to give the 3rd prize
97 ways to give the last prize
∴ P(99,3) = 99 x 98 x 97
b). 1 way to give person 47 their prize
1 way to give person 19 their prize
98 ways to give out the 3rd prize
97 ways to give out the last prize
So, P(98,2) = 98 x 97
To find the percent you take 18 and divide it by 48, so you get 9/24 or 3/8, by using calculator you get .375 which is 37.5% then you multiply by 100 to convert a decimal to a percentage.
500 (the current collection) + 10 (the weekly addition) x 20 (weeks to add)
500 + 10*20 (Multiplication comes before addition)
500+200
700
another way I can phrase it
500 total right now
each week he adds 10
after 20 weeks he will have x books
20 weeks=10 times 20 books added=200 books added
500+200=700
answer is 700