Question

Three friends went to a hotel and had breakfast to their taste, paying Rs.16, Rs.17 and Rs.21 respectively
(i) Find their mean expenditure.
(ii) If they have spent 3 times the amount that they have already spent, what would their mean expenditure be?
(ii) If the hotel manager offers 50% discount, what would their mean expenditure be?
(iii) Do you notice relationship between the change in expenditure and the change in mean expenditure.

Answer 1

Dear Student,

Solution:

(i) Find their mean expenditure:

Total person = 3

Their expense on breakfast= 16 ,17 and 21 Rupees

Mean
$= \frac{16 + 17 + 21}{3} \\ \\ = \frac{54}{3} \\ \\ = 18$



their mean expenditure on breakfast is 18 Rupees.

(ii) If they have spent 3 times the amount that they have already spent, what would their mean expenditure be?

Answer :
Mean
$= \frac{16 \times 3 + 17 \times 3 + 21 \times 3}{3} \\ \\ = \frac{48 + 51 + 63}{3} \\ \\ = 54$


(iii) If the hotel manager offers 50% discount, what would their mean expenditure be?
Mean
$= \frac{48 \times \frac{50}{100} + 51 \times \frac{50}{100} + 63 \times \frac{50}{100} }{3} \\ \\ = \frac{24 + 25.5 + 31.5}{3} \\ \\ = \frac{81}{3} \\ \\ = 27$




(iv) Do you notice relationship between the change in expenditure and the change in mean expenditure.

Answer: if all the values increased by a constant factor 'a' ,than new mean = a x old mean.
case 2) new mean = 3*18=54

According to property: if all the values decreased by a constant factor '1/a' ,than new mean = 1 /a x old mean.
= 54*50/100
= 27

Answer 2

Answer:

Step-by-step explanation: