Answer:
1.30 p.M.
Step-by-step explanation:
The factory whistle blowed at 1:00 p.M, and it blows every 30 minutes, so it will blow again at 1:30 p.M.
The clock tower chimed at 1.00 p.M., and it chimes every 15 minutes, so it will chime again at 1:15 p.M, and after that, it will chime again at 1:30 p.M.
So, you will hear them both at the same time at 1:30 p.M.
We can also solve this problem using LCM:
the least commom multiple between 15 and 30 is 30, so we just need to sum 30 to the inicial time (1:00 p.M.), so the time they will "find each other" again is 1.30 p.M.
Big/small=4/7
r1/r2=4/7 where r1, r2 are radius of a big and small circles respectively
r1/3=4/7
r1=12/7
circumference of a big circle is2πr1=2π*12/7=24π/7 cm
Answer:
(5, -3)
y= -3
x= 5
Step-by-step explanation:
-x-2y=1
x+y=2
solve the equation
-x-2y=1
x=2-y
substitute the value of x into an equation
-(2-y)-2y=1
remove parenthesis
-2-y-2y=1
subtract y to 2y
-2-y=1
add 2 from both sides
-y=3
divide both sides by -y
y= -3
substitute the value of y into an equation
x=2-(-3)
remove parenthesis
x=2+3
add 2 to 3
x=5
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(5,-3)
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Since it is not mentioned in the problem, we will assume that repeating of number is allowed.
For the first wheel, you have 10 possible digits.
For the second wheel, you have 10 possible digits.
For the third wheel, you have 10 possible digits.
10 x 10 x 10 = 1000
The probability that someone randomly guesses the correct combination in his first attempt is 1/1000.
If this was without repeat, then
10*9*8 = 720
The probability that someone randomly guesses the correct combination in his first attempt is 1/720.
