ans is b...multiply eqn 1 by -2 and eqn 2 by 3
=》 -6x + 10y = 4...eqn 3
=》 6x + 3y = 9...eqn 4
add eqn 3 and 4...
=》13y = 13
=》y =1 and x = 1
If we assume that
x isthe number of multiple choice questions, and y is the number of word problems, we can write a system of equations like:
{ x + y = 38
{ 2x + 5y = 100
If we multiply the first equation by -2 we get:
{ -2x-2y = -76
{ 2x + 5y = 100
Now if we add both equations we get only equation with 1 unknown (y) :
3y = 24 ⇒ y = 8
Substituting the calculated value to the first equation we get:
x + 8 = 38 ⇒ x = 30
The solution:
{ x = 30
{ y = 8
means that:
The test had 30 multiple choice questions, and 8 word problems.
Segment DF is 1/2 the length of Segment DE. Since the entire segment is DE and it's midpoint is at F, the segment would be broken into 2 equal segments in one. Segment DF and FE. Segment DF is congruent to Segment FE.
Answer:
0.6804
Step-by-step explanation:
Given that Margie is practicing for an upcoming tennis tournament. Her first serve is good 20 out of 30 times on average.
Since each trial is independent and there are two outcomes, X no of good serves is binomial with n=6 and p =2/3
Required probability
= Prob that atleast four of 6 times good serve
=
=
Formula used:
P(X=r) =
Answer:
Animal books make up (3/20) of all books
Step-by-step explanation:
Let X be the total number of books, made up of nonfiction, animal, and all others.
(3/5)X are nonfiction books.
Of the nonfiction books, 1/4 are animal books: (3/5)*(1/4)X = (3/20)X are animal books
[This means that Nonfiction, less animal books is: (3/5)X - (3/20)X]
Animal books make up (3/20) of all books.