Kenya Math Challenge

Solve for x: 2x + 5 = 15

• x = 7

• x = 5

• x = 3

• x = 10

Answer explanation

To solve for x, subtract 5 from both sides: 2x = 10. Then divide by 2 to get x = 5. Therefore, x = 5 is the correct choice.

Calculate the area of a triangle with base 6 cm and height 8 cm

• 24 square cm

• 14 square cm

• 48 square cm

• 30 square cm

Answer explanation

To calculate the area of a triangle, use the formula: Area = 0.5 * base * height. Substituting the values, Area = 0.5 * 6 cm * 8 cm = 24 square cm. Therefore, the correct answer is 24 square cm.

Find the value of sin(60 degrees)

• √3/2

• 2

• 0

• 1

• 1/2

Answer explanation

The value of sin(60 degrees) is √3/2, which is the correct choice.

Calculate the mean of the following data set: 10, 15, 20, 25, 30

• 20

• 18

• 22

• 28

Answer explanation

The mean is calculated by adding all numbers together and dividing by the total count. (10+15+20+25+30)/5 = 20. Therefore, the mean of the data set is 20.

Differentiate y = 3x^2 + 5x - 2

• dy/dx = 6x - 2

• dy/dx = 3x^2 + 5

• dy/dx = 3x^2 + 5x

• dy/dx = 6x + 5

Answer explanation

To differentiate y = 3x^2 + 5x - 2, apply the power rule to get dy/dx = 6x + 5. Therefore, the correct choice is dy/dx = 6x + 5.

What is the probability of rolling a prime number on a fair six-sided die?

• 1/3

• 1/5

• 1/2

• 1/4

Answer explanation

The probability of rolling a prime number on a fair six-sided die is 1/2 because there are three prime numbers (2, 3, 5) out of a total of six possible outcomes.

Solve the equation: 3x + 7 = 16

• x = 2

• x = 10

• x = 3

• x = 5

Answer explanation

To solve the equation 3x + 7 = 16, first subtract 7 from both sides to get 3x = 9. Then, divide by 3 to find x = 3. Therefore, the correct answer is x = 3.

Find the volume of a cylinder with radius 4 cm and height 10 cm

• 502.4 cm^3

• 604.4 cm^3

• 200.4 cm^3

• 402.4 cm^3

Answer explanation

The formula for the volume of a cylinder is V = πr^2h. Substituting r=4 cm and h=10 cm, V = π(4^2)(10) = 502.4 cm^3. Therefore, the correct answer is 502.4 cm^3.

If tan(theta) = 3/4, find sin(theta)

• 5/4

• 4/5

• 2/3

• 3/5

Answer explanation

Given tan(theta) = 3/4, we can use the Pythagorean identity to find sin(theta). sin(theta) = 3/5, so the correct answer is 3/5.

Integrate f(x) = 2x^3 + 5x^2 - 3x + 7

• (1/2)x^4 + (5/3)x^3 - (3/2)x^2 + 7x + C

• (1/2)x^4 + (5/3)x^3 - (3/2)x^2 + 7x + C + D

• (1/2)x^4 + (5/3)x^3 - (3/2)x^2 + 7x

• (1/2)x^4 + (5/3)x^3 - (3/2)x^2 + 7

Answer explanation

To integrate f(x) = 2x^3 + 5x^2 - 3x + 7, apply the power rule for integration. The integral is (1/2)x^4 + (5/3)x^3 - (3/2)x^2 + 7x + C, where C is the constant of integration.