In winter, the temperature at a hill station from Monday to Friday is in A.P. The sum of the temperatures of Monday, Tuesday and Wednesday is zero and the sum of the temperatures of Thursday and Friday is 15. Find the temperature of each of the five days.


4. In winter, the temperature at a hill station from Monday to Friday is in A.P. The sum of the temperatures of Monday, Tuesday and Wednesday is zero and the sum of the temperatures of Thursday and Friday is 15. Find the temperature of each of the five days.

Sol. Let the temperatures of hill station from Monday to Friday which form are A.P. be a – 2d, a – d, a, a + d, a + 2d respectively.

As per the first condition,

a – 2d + a – d + a = 0
 3a – 3d = 0
 3 (a – d) = 0
 a – d = 0
 a = d

As per the second condition,

a + d + a + 2d = 15
 2a + 3d = 15
2a + 3a = 15 [ a = d]
5a = 15
a = 15/5
a = 3
 d = 3 [ d = a]
 a – 2d = 3 – 2 (3) = 3 – 6 = – 3
 a – d = 3 – 3 = 0
 a + d = 3 + 3 = 6
 a + 2d = 3 + 2 (3) = 3 + 6 = 9
The temperatures from Monday to Friday are – 30C, 00C, 30C, 60C and 90C respectively