| 181 |
Pipes A and B can fill a tank in 20 minutes and 30 minutes. Both are opened together, and B is closed after 6… |
Mathematics/Applied Mathematics
Pipes and cisterns |
Hard |
| 182 |
In a 100 m race, A beats B by 10 m. This means that when A finishes, B has run |
Mathematics/Applied Mathematics
Races and games |
Easy |
| 183 |
A runs 100 m in 20 seconds and B runs 100 m in 25 seconds. By how many seconds does A beat B in a 100 m race? |
Mathematics/Applied Mathematics
Races and games |
Easy |
| 184 |
A runs 100 m in 20 seconds and B runs 100 m in 25 seconds. By how many metres does A beat B in a 100 m race? |
Mathematics/Applied Mathematics
Races and games |
Medium |
| 185 |
In a 1 km race A beats B by 100 m, and in a 1 km race B beats C by 100 m. By how much does A beat C in a 1 km… |
Mathematics/Applied Mathematics
Races and games |
Medium |
| 186 |
In a 200 m race, A gives B a start of 20 m and still beats B by 10 m. The ratio of the speeds of A and B is |
Mathematics/Applied Mathematics
Races and games |
Hard |
| 187 |
The statement "a person must be at least 18 years old to vote", with age x in years, is written as |
Mathematics/Applied Mathematics
Numerical inequalities |
Easy |
| 188 |
The solution of 3x − 5 < 7 is |
Mathematics/Applied Mathematics
Numerical inequalities |
Easy |
| 189 |
A student scored 70 and 75 in two tests. What must she score in the third test so that her average over the t… |
Mathematics/Applied Mathematics
Numerical inequalities |
Medium |
| 190 |
The solution of the inequality −2x ≥ 6 is |
Mathematics/Applied Mathematics
Numerical inequalities |
Medium |
| 191 |
The set of real numbers x satisfying |x − 3| < 2 is |
Mathematics/Applied Mathematics
Numerical inequalities |
Hard |
| 192 |
If y = x³ − 4x, the value of d²y/dx² at x = 2 is: |
Mathematics/Applied Mathematics
Derivatives in applications |
Easy |
| 193 |
If x = 2t + 1 and y = t³, the value of dy/dx at t = 2 is: |
Mathematics/Applied Mathematics
Derivatives in applications |
Easy |
| 194 |
The slope of the tangent to the curve xy = 12 at the point (3, 4) is: |
Mathematics/Applied Mathematics
Derivatives in applications |
Medium |
| 195 |
The radius of a spherical balloon increases at 2 cm/s. How fast is its volume increasing when the radius is 5… |
Mathematics/Applied Mathematics
Derivatives in applications |
Medium |
| 196 |
If x = a cos t and y = a sin t, then d²y/dx² equals: |
Mathematics/Applied Mathematics
Derivatives in applications |
Hard |
| 197 |
Marginal cost is best described as: |
Mathematics/Applied Mathematics
Marginal cost and marginal revenue |
Easy |
| 198 |
If the total revenue from selling x units is R(x) = 3x² + 36x + 5, the marginal revenue when x = 5 is: |
Mathematics/Applied Mathematics
Marginal cost and marginal revenue |
Easy |
| 199 |
The total cost of producing x units is C(x) = 0.005x³ − 0.02x² + 30x + 5000. The marginal cost when 3 units a… |
Mathematics/Applied Mathematics
Marginal cost and marginal revenue |
Medium |
| 200 |
The demand function for a product is p = 50 − 2x. For what output x is the marginal revenue zero? |
Mathematics/Applied Mathematics
Marginal cost and marginal revenue |
Medium |