In a winter season let us take the temperature of Ooty from Monday to Friday to be in A.P. The sum of temperatures from Monday to Wednesday is 0° C and the sum of the temperatures from Wednesday to Friday is 18° C. Find the temperature on each of the five days.
Solution :
Let the temperature of Ooty from Monday to Friday are
a - 2d, a - d, a, a + d , a + 2d
a - 2d + a - d + a = 0
3a - 3d = 0
a - d = 0 ---(1)
a + a + d + a + 2d = 18
3a + 3d = 18
a + d = 6 ---(2)
(1) + (2)
a + a = 6
2a = 6
a = 3
By applying the value of a in (1), we get
3 + d = 6
d = 6 - 3
d = 3