The result of rolling a number cube 7 times is a 7-digit number composed of digits 1,2,3,4,5 and 6 so that digits can repeat. The total number of possibilities is 6^7.
The number of possibilities where 4 appears exactly two times is 5^5*(7!-6!/2).
5^5 is the number of 5-digits numbers composed of digits 1,2,3,5 and 6 so that digits can repeat.
7! is the number of permutations of digits 1,2,3,4,4,5 and 6.
6! is the number of permutations of digits 1,2,3,{4,4},5 and 6.
We don't want to subtract all numbers where digits 4 appear side by side. That's why we must divide 6! by 2.
Finally, the probability is P=5^5(7!-6!/2)/7^7
Answer:
87-88
Step-by-step explanation:
Answer:
1 ± i(1/2)√2
Step-by-step explanation:
Write this quadratic in standard form: subtract 3 from both sides. This results in 2x^2 - 4x - 3 = 0. Let's apply the quadratic formula. The coefficients of the x terms are 2, -4 and -3, so the discriminant is (-4)^2 - 4(2)(-3), or 16 - 24 = -8.
Following the format of the quadratic formula, we get
-(-4) ±i2√8 4 ±i2√2
x = ----------------- = --------------- = 1 ± i(1/2)√2
4 4
Answer:
6
Step-by-step explanation:
80-38= 42
You need $42
at 7 per car... 42/7= 6