Practice China questions with answers and explanations.
By Vieta’s formula, the sum of the roots equals the coefficient 15.
aₙ=a₁+(n−1)d=8+(8−1)×4=36.
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The sum is n(n+1)/2=15, so the mean is 15/5.
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There are 2 favourable outcomes out of 8 equally likely outcomes, so P(red)=2/8.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=3x²+6x. Substituting x=4 gives 72.
An antiderivative is 3/2 x²+5x. At x=4, the value is 44.0.
The dot product is 3×4+6×3=30.
Rewrite the value using base 4: 256 = 4^4. Matching exponents gives x = 4.
aₙ=a₁+(n−1)d=7+(7−1)×3=25.
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The sum is n(n+1)/2=10, so the mean is 10/4.
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There are 6 favourable outcomes out of 11 equally likely outcomes, so P(red)=6/11.
