When a a person calculated his expense from Sunday to Thursday he found the average expenditure to be 400 rupees per day .including Friday the average increased to 430 rupees per day. how much did he spend on Friday ?including Saturday ,the average decreased to 390 rupees per day. how much did he spend on Saturday?
Answers
Answer:
The expenses on Friday = Rs 580
The expenses on Saturday = Rs 150
Explanation:
Let the expenses on Sunday = x1
Let the expenses on Monday = x2
Let the expenses on Tuesday = x3
Let the expenses on Wednesday = x4
Let the expenses on Thursday = x5
Let the expenses on Friday = x6
The average expenses from Sunday to Thursday = Rs 400 per day
(x1 + x2 + x3 + x4 + x5)/5 = 400
=> x1 + x2 + x3 + x4 + x5 = 2000
The average expenses from Sunday to Thursday = Rs 430 per day
(x1 + x2 + x3 + x4 + x5 + x6)/6 = 430
x1 + x2 + x3 + x4 + x5 + x6 = 2580
=> 2000 + x6 = 2580
=> x6 = 2580 — 2000
=> x6 = 580
The average expenses from Sunday to Saturday = Rs 390 per day
(x1 + x2 + x3 + x4 + x5 + x6 + x7)/7 = 390
x1 + x2 + x3 + x4 + x5 + x6 + x7 = 2730
=> 2580 + x7 = 2730
=> x7 = 2730 — 2580
=> x7 = Rs 150
Therefore,
The expenses on Friday = x6 = Rs 580
The expenses on Saturday = x7 = Rs 150