the cost of 8 apples and 5 mangoes is rs194. the cost of 5 guvavas and 6 mangoes is rs183. the cost of 7 apples and 9 guvavas is rs226.
what is the cost of 3 mangoes, 2 guvavas and 1 apple together ?
Answers
Solution :-
8A + 5M = 194 ------- Equation ❶
5G + 6M = 183 ------- Equation ❷
7A + 9G = 226 ------- Equation ❸
Now 6*(Equation ❶) - 5(Equation ❷) , we get :-
➺ 6(8A + 5M) - 5(5G + 6M) = 6*194 - 5*183
➺ 48A + 30M - 25G - 30M = 1164 - 915
➺ 48A - 25G = 249 -------- Equation ❹
________________________
Now, Equation ❸ + (9/25)[Equation ❹] we get,
➻ (7A + 9G) + [(9/25)(48A - 25G)] = 226 + [(9/25) * 249]
➻ [7A + (48*9A/25)] = (249*9/25) + 226
⟪ Now, Here we have use a Little approximation for making calculation easy (48/25) = 2 & (249/25) = 10. ⟫
So,
➻ (7A + 2*9A) = 10*9 + 226
➻ 25A = 316
➻ A ≈ 13 .
______________________
Putting value of A in Equation ❶ :-
⟼ 8*13 + 5M = 194
⟼ 5M = 194 - 104
⟼ 5M = 90
⟼ M = 18
________________
Putting value of M in Equation ❷ Now :-
⟿ 5G + 6*18 = 183
⟿ 5G = 183 - 108
⟿ 5G = 75
⟿ G = 15
___________________
Hence, we have :-
☞ A = 13
☞ M = 18
☞ G = 15
Therefore,
☛ Cost of (3M + 2G + A)
☛ (3*18 + 2*15 + 13)
☛ (54 + 30 + 13)
☛ Rs.97 (Ans.)
QUESTION :
the cost of 8 apples and 5 mangoes is rs194. the cost of 5 guvavas and 6 mangoes is rs183. the cost of 7 apples and 9 guvavas is rs226.
what is the cost of 3 mangoes, 2 guvavas and 1 apple together ?
CONCEPT USED :
Solving a system of Linear equations.
SOLUTION :
From the above Question, we can derive the following equations.
First let us assume the following...
Let the cost of 1 Apple be Rs. A
Let the cost of 1 Mangoe be Rs. M
Let the cost of 1 Guava be Rs. G
So, we can form :
8 A + 5 M = 194....... ( 1 )
5 G + 6 M = 183. ........... ( 2 )
7 A + 9 G = 226. ... ..... ( 3 )
TO FIND :
3M + 2 G + 1 A = ?
CALCULATION :
From equation 1, we can form :
5 m = - 8 A + 194
=> m = { - 8 / 5 } A + { 194 / 5 }........ ( 5 )
Substituting this in Equation 2..
=> 5 G + 6 { { - 8 / 5 } A + { 194 / 5 } } = 183
=> 5 G + { -48 / 5 } A + { 194 / 5 } = 183
=> 5 G = { 48 / 5 } A + 183 - { 194 / 5 }
=> 5 G = { 48 / 5 } A - { 721 / 5 }
=> G = { 48 / 25 } A - { 721 / 25 }......... ( 6 )
Substituting this in Equation 3..
=> 7 A + 9 G = 226
=> 7 A + 9 { { 48 / 25 } A - { 721 / 25 } } = 226
Solving for A, we get :
A = 13
Substituting for G , we get :
G = { 48 / 25 } × 13 - { 721 / 25 }
=> G = 15
Substituting for M , we get :
=> M = { - 8 / 5 } A + { 194 / 5 }
Solving,
M = 18.
Cost of 3 mangoes = 3 × 18 = Rs. 54
Cost of 2 Guavas = 2 × 15 = Rs. 30
Cost of 1 Apple = Rs. 13
Hence, the total cost comes out to be Rs. 97
ANSWER :
Therefore the cost of 3 mangoes, 2 guvavas and 1 apple together is Rs. 97.