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?
(iii) If the hotel manager offers 50% discount, what would their mean expenditure be?
(iv) Do you notice any relationship between the change in expenditure and the change in mean expenditure?
Let three friends be A, B and C
According to the question,
Expenditure of A =Rs.16
Expenditure of B =Rs.17
Expenditure of C =Rs.21
(i) Their mean expenditure
=16+17+213=543=Rs. 18
(ii) New expenditure of A =Rs.16×3=Rs. 48
New expenditure of B =Rs.17×3=Rs. 51
New expenditure of C =Rs.21×3=Rs. 63
Their new mean expenditure
=48+51+633=1623=Rs. 54
(iii) Total amount =Rs. 54
After 50% discount, net amount to be paid =54×50100=Rs.27
Their mean expenditure is,
=273=Rs. 9
(iv) New expenditure =3× Original one
And, New mean expenditure =3× Original one (Mean expenditure)
The change in the expenditure and the change in the mean expenditure are proportionate to each other.