There are 62 dimes and 44 nickels.
N + D = 106 (There are 106 coins in all.)
1 nickel = 5 cents.
1 dime = 10 cents.
5*N + 10*D = 840 ($8.40 = 840 cents)
N + D = 106 -------(1)
N = (106 - D)
5*N + 10*D = 840 ---------(2)
5*(106-D) + 10*D = 840
530 - 5*D + 10*D = 840
5*D = 840 - 530
5*D = 310
D = 310/5 = 62
Eq(1) N + D = 106
N + 62 = 106
N = 106 - 62
N = 44
Answer:
Answer b
Step-by-step explanation:
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Answer:
12 pull
As 48 seconds + 20 seconds push = 68 seconds
Step-by-step explanation:
Because she did 10 push = 20 seconds = 2 seconds each
12 pull = 48 seconds = 4 seconds each
= 68 seconds combined.
Workings;
18 seconds found for the first set
We then find a divider of 68 and know that
6 x 3 = 18 seconds push
12 x 3 =36 seconds pull T= 54
14 left over = 1 x 12 seconds pull
+ 2 seconds push
= 10 push = 20 seconds combined.
= 12 pull = 48 seconds combined.
Answer:
Step-by-step explanation:
a) Denote the event of commercially availability of f_uel cell technology as F_, commercial availability of solar power technology as S
Write the probability of energy supplied by these energy sources in the next 10 years
P(energy supplied) = P(S ∪ F) -----(1)
Rewrite eqn (1)
P(energy supplied) = P(S) + P(F) - P(F) P(S) ----(2)
substitute 0.85 for P(S) and 0,7 for P(F) in eqn (2) to find the probability of energy supplied by these energy sources
P(energy supplied) = 0.85 + 0.7 - (0.7 * 0.85)
= 0.85 + 0.7 - (0.595)
= 1.55 - 0.595
= 0.955
Therefore, the probability that there will be energy supplied by these two alternative sources in the next 10 years is 0.955
B) write the probability of only one source of energy available
P(only one source of energy available) =
∪
---(3)
Rewrite the equation (3)
P(only one source of energy available) =
![=P(\bar F S)+P(\bar S F)\\\\=\{[1-P(F)]P(S)+[1-P(S)]P(F)\}---(4)](https://tex.z-dn.net/?f=%3DP%28%5Cbar%20F%20S%29%2BP%28%5Cbar%20S%20F%29%5C%5C%5C%5C%3D%5C%7B%5B1-P%28F%29%5DP%28S%29%2B%5B1-P%28S%29%5DP%28F%29%5C%7D---%284%29)
![=\{[1-0.7]0.85+[1-0.85]0.7\}\\\\=0.255+0.105\\\\=0.36](https://tex.z-dn.net/?f=%3D%5C%7B%5B1-0.7%5D0.85%2B%5B1-0.85%5D0.7%5C%7D%5C%5C%5C%5C%3D0.255%2B0.105%5C%5C%5C%5C%3D0.36)
Therefore,The probability that only one of the two alternative energy sources will be commercially viable in the next 10 years is 0.36