Question

The price of 6 chocolates 3 biscuit packet together is 120 rupees. The price of 10 chocolates and 3 biscuits packet is 186 rupees. What is the price of chocolate and what is the price of biscuit packet​

Answer 1

GIVEN :-

• 6 chocolates and 3 biscuits cost 120 rupees

• 10 chocolates and 3 biscuits cost 186 rupees

TO FIND :-

• price of chocolate and biscuit

SOLUTION :-

let the number of chocolate be x

and the number of biscuits be y

so according to question :-

$\implies\rm{6x + 3y = 120}$

$\implies\rm{ \bf{2x + y = 40}} \: \: \: \: \: \: \: (1)$

now for 2nd condition

$\implies\rm{ \bf{10x + 3y = 186}} \: \: \: \: \: \: (2)$

now taking eq (1)

$\implies\rm{2x + y = 40}$

$\implies\rm{ \bf{y = 40 - 2x}} \: \: \: \: \: \: (3)$

now by using SUBSTITUTION METHOD,

putting the value of y in eq (2) from eq (3)

$\implies\rm{10x + 3y = 186}$

$\implies\rm{ 10x + 3(40 - 2x) = 186}$

$\implies\rm{ 10x + 120 - 6x= 186}$

$\implies\rm{ 10x - 6x= 186 - 120}$

$\implies\rm{ 4x= 186 - 120}$

$\implies\rm{ 4x= 66}$

$\implies \boxed{\rm{ x= 16.5}}$

now putting the value of x in eq 3

$\implies\rm{ y = 40 - 2x}$

$\implies\rm{ y = 40 - 2(16.5)}$

$\implies \rm{y = 40 - 33}$

$\implies \boxed{\rm{y = 7}}$

HENCE ,

$\implies \boxed{ \boxed{ \rm{chocolate = 16.5 \: rs \: , \:biscuit = 7 \: rs}}}$