Question

A contract on construction job specifies a penalty for delay of completion beyond a certain date as follows: Rs.200 for the first day,Rs.250 for the second day, Rs.300 for the third day,etc.., The penalty for each succeeding day being Rs.50 more than for the preceding day. How much money the contractor has to pay as penalty, if he has delayed the work by 30 days??​

Answer 1

Penalty for 1st day= 200

Penalty for 2nd day=250

Penalty for 3rd day = 300

Hence the series is

200,250,300...

Since difference is the same, it is AP

Common difference=d=50

We need to find total penalty if work is delayed by 30 days

i.e. we need to fins s₃₀

We know that

$Sn=\frac{n}{2} (2a+(n-1)d)$

Putting n= 30 , a = 200, d = 50

30/2(2x200+(30-1)x50)

=15(400+1450)

=15x1850

=27750

Hence,the total penalty if works is delayed by 30 days is Rs 27750