Practice China questions with answers and explanations.
Choose an option to check your answer.
The sum is n(n+1)/2=28, so the mean is 28/7.
Choose an option to check your answer.
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+10x. Substituting x=2 gives 32.
An antiderivative is 2/2 x²+1x. At x=3, the value is 12.0.
The dot product is 2×2+2×4=12.
Rewrite the value using base 3: 27 = 3^3. Matching exponents gives x = 3.
Choose an option to check your answer.
Use the circle-area formula A = πr². Substituting r = 7 gives A = π × 7² = 49π.
Percentage=(10/35)×100=28.57.
Percentage=(9/34)×100=26.47.
Subtract 3 from both sides and divide by 5: x = (13-3)/5 = 2.
By Vieta’s formula, the sum of the roots equals the coefficient 10.
