Answer:
19? 21?
Step-by-step explanation:
Answer:
x= 7.5 mile/h
y= 3.5 miles / h
Step-by-step explanation:
Given x and y
so, x+y = speed down river
and x-y= speed up river
using
travel time = distance / speed for each case;
we get;
22/x+y=2 ---(1)
and
22/x-y=5.5 -----(2)
Solving equations simultaneously
eq 1 gives
2x+2y=22 ---(3)
eq 2 gives
5.5x-5.5y=22 ----(4)
Multiply eq 3 by 2.75
==> 5.5x+5.5y=60.5 --- (5)
adding eq 4 with eq 5
==> 11x =82.5
==> x= 7.5 miles/h
put this value in eq 3
==> 2(7.5)+2y=22
==> 2y=22-19.8
==> 2y=7
==> y = 3.5
A Pythagorean triple consists of three positive integers a, b, and c, such that a2 + b2 = c2. Such a triple is commonly written (a, b, c), and a well-known example is (3, 4, 5). If (a, b, c) is a Pythagorean triple, then so is (ka, kb, kc) for any positive integer k.
The probability that you will guess the first answer correctly = 1/2 = 0.5
The probability that you will guess the second answer correctly = 1/2 = 0.5
The probability that you will guess the third answer correctly = 1/2 = 0.5
The probability that you will guess all three answers correctly is
(0.5) x (0.5) x (0.5) = 0.125 = 12.5% .
============================
Here are all the ways your answer sheet could wind up:
(R = a right answer. W = a wrong answer.)
W W W
W W R
W R W
W R R
R W W
R W R
R R W
R R R
Number of possible ways to score 0 right out of 3 questions: 1 way
Number of possible ways to score 1 right out of 3 questions: 3 ways
Number of possible ways to score 2 right out of 3 questions: 3 ways
Number of possible ways to score 3 right out of 3 questions: 1 way
Statistically, if your answers are all pure guesses,
then on the average, the score you expect is
(0 + 33-1/3 + 33-1/3 + 33-1/3 + 66-2/3 + 66-2/3 + 66-2/3 + 100) / 8
= 400 / 8
= 50% .
If you're happy with that score, great !
Go to the movies the night before the test,
and start guessing.
0.739 is the answer that I got (this is not a rounded answer by the way)
hope it helps :)
