Two towns, P and Q, are on (4oN 40oW) and (4oN 20oE) respectively. What is the distance between them, along their line of latitude? (Give your answer in tee...

To find the distance between towns P and Q along their line of latitude, we need to calculate the length of the arc formed by the angle between the two towns and the center of the Earth. The distance between P and Q can be calculated using the formula: Distance = angle (in radians) x radius of the Earth First, we need to find the angle between P and Q. Since both towns are on the same line of latitude, the angle between them is simply the difference between their longitudes, which is: 20^oE - 40^oW = 60^o Next, we need to convert this angle to radians by multiplying it by π/180, since there are π radians in 180 degrees. 60^o x π/180 = π/3 radians Finally, we can plug this value into the formula for distance: Distance = angle (in radians) x radius of the Earth = (π/3) x R = (πR)/3 Therefore, the correct answer is: Option (d) is the correct answer.