Answer:
45 ways
Step-by-step explanation:
We are given;
there are 3 different math courses, 3 different science courses, and 5 different history courses.
Thus;
Number ways to take math course = 3
The number of ways to take science course = 3
The number of ways to take history course = 5
Now, if a student must take one of each course, the different ways it can be done is;
possible ways = 3 x 3 x 5 = 45 ways.
Thus, number of different ways in which a student must take one of each subject is 45 ways.
Answer:A
Step-by-step explanation:
In the first 100 pages there are 10 pages with numbers 40-49 ( that is total of 11 4's) and another 4 in the units, 10's , 20's, .... 90's ( not including 40's) That is total of 9 4's.
So in first 100 pages there are 20 4's.
therefore there are 20 4's on pages 101-200 and another 20 4's on pages 201-300.
On pages 301 to 352 there are 15 4's.
answer is 3*20 + 15 = 75.
Answer:
367
Step-by-step explanation:
Let a, b be two odd integers. Then both can be written as
a=2k-1, k is an integer
b=2m-1, m is an integer
So,
a-b=2k-1-(2m-1)=2k-2m-2=2(k-m-1)
Since, k and m and 1 are all integers, then (k-m-1) is also an integer. Hence, 2(k-m-1) is an even integer.
Thus, a-b is even.
