Practice China questions with answers and explanations.
Rewrite the value using base 3: 27 = 3^3. Matching exponents gives x = 3.
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Use the circle-area formula A = πr². Substituting r = 3 gives A = π × 3² = 9π.
Percentage=(6/21)×100=28.57.
Subtract 5 from both sides and divide by 4: x = (17-5)/4 = 3.
By Vieta’s formula, the sum of the roots equals the coefficient 11.
aₙ=a₁+(n−1)d=4+(7−1)×3=22.
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The sum is n(n+1)/2=21, so the mean is 21/6.
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There are 4 favourable outcomes out of 9 equally likely outcomes, so P(red)=4/9.
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The sum is n(n+1)/2=15, so the mean is 15/5.
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There are 3 favourable outcomes out of 7 equally likely outcomes, so P(red)=3/7.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=6x²+6x. Substituting x=2 gives 36.
