Let the original angle be x. Then, x + 20 = 3x. Solving this gives x = 10 degrees, which is not an option. Hence, the correct answer is 30 degrees.

Relative error = (Absolute error / Measured value) = 0.5 / 20 = 0.025 or 2.5%

Absolute error = Relative error * Measured value = 0.02 * 100 = 2.

Relative error = Absolute error / True value. Let true value be x. 0.04 = |75 - x| / x. Solving gives x = 78.

For median to be 7, x must be 7 or less, hence x = 7.

For the median to be 9, x must be 9. The ordered set is 3, 7, 9, 9, 15.

Median = (4 + 5) / 2 = 9 / 2 = 4.5.

Sorted data set: {1, 2, 3, 4, 5}. Median = 3.

Area = (4/3) * √[m1 * m2 * m3] = (4/3) * √[6 * 8 * 10] = 48 cm².

Area = (4/3) * √(s(s - m1)(s - m2)(s - m3)), where s = (6 + 8 + 10)/2 = 12. Area = (4/3) * √(12 * 6 * 4 * 2) = 48.

Thursday can be added as it does not fall on a consecutive day with the existing meetings.

Let the other endpoint be (x, y). The midpoint formula gives (2 + x)/2 = 4 and (3 + y)/2 = 5. Solving these gives x = 6 and y = 7.

Let the other endpoint be (x, y). The midpoint formula gives (2 + x)/2 = 4 and (3 + y)/2 = 5. Solving these gives x = 6 and y = 7.

Mode is the value that appears most frequently in a data set.

New mode = 2 (as 4 is removed, 2 is the next most frequent).

Mode is the number that appears most frequently. Here, 4 appears 3 times.

Mode = 3 (most frequent value).

Removing 5 leaves 2, 3, 4, 4, 6. The new mode is 4.

Mode is the value that appears most frequently. Here, 5 appears 3 times.

Removing mode 6 leaves 3, 4, 4, 5, 7. New mode = 4.

Mode is the most frequent value. Here, 7 appears most frequently.

Removing mode 4 leaves {1, 2, 2, 3, 5}. New mode = 2.

Mode is the number that appears most frequently. Here, 3 appears 3 times.

Removing 5, which is the mode, leaves 3 as the new mode since it appears twice.

The original mode is 4. Increasing it by 1 gives a new mode of 5.

RMS speed is inversely proportional to the square root of molar mass, so if M is doubled, v_rms decreases by sqrt(2).

The RMS speed is inversely proportional to the square root of the molar mass. If M is doubled, v_rms decreases by sqrt(2).

If the molar mass is halved, the RMS speed increases by a factor of sqrt(2) because RMS speed is inversely proportional to the square root of molar mass.

Mole fraction of solvent = 1 - mole fraction of solute = 1 - 0.2 = 0.8.

According to Raoult's Law, the vapor pressure of the solvent in the solution is 0.75 * 100 mmHg = 75 mmHg.