Answer:
Step-by-step explanation:
the first marble has a probability of 2/5
the second marble has a probability of 1/4
P(r=2) = 2/5 * 1/4 = 2/20 = 1/10
C/3 = 6 1/7
Multiply 3 to both sides:
C = 6 1/7 * 3
Convert 6 1/7 into an improper fraction:
C = 43/7 * 3
Multiply 3 to the numerator:
C = 129/7
Convert back into a mixed number:
C = 18 3/7
Answer:
D
Step-by-step explanation:
The perimeter of answer A is 6+6+8+8 which is 12+16=28
The perimeter of answer B is 7+7+7+7 which is 28
The perimeter of answer C is 7+7+6+6 which is 14+12=26
The perimeter of answer D is 9+9+6+6 which is 18+12 which is 30
Step-by-step explanation:
Let the number of books of Physics be x . Then , No. of chemistry books =3.5x
Now , according to question :
x+3.5x=90
Or , 4.5x=90
Or , x=90/4.5
Or , x=20
Now ,
3.5x= 3.5×20
= 70
Therefore , there were 70 chemistry books and 20 physics books in that question bank.
