Answer:
A)
![x+y=20](https://img.qammunity.org/2021/formulas/mathematics/college/5mer5qz67ufzichbtam5w4f0fpvcyt3ovp.png)
B) Cost function is:
![3x+2y = 50](https://img.qammunity.org/2021/formulas/mathematics/high-school/raxk5o44yxw82bsxz06psa6do28dudz7p0.png)
C)
,
![3x+2y = 50](https://img.qammunity.org/2021/formulas/mathematics/high-school/raxk5o44yxw82bsxz06psa6do28dudz7p0.png)
D)
![x=10, y=10](https://img.qammunity.org/2021/formulas/mathematics/high-school/mzc9bszzjezutq7prl023h0smikqdwxoh5.png)
E) Yes, the result satisfies the equations.
Explanation:
Let number of kilos of mango bought =
![x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/p9sq9b3rc5nwoqzhzc8wcaj51b36281l9g.png)
Let number of kilos of atis bought =
![y](https://img.qammunity.org/2021/formulas/mathematics/middle-school/kkh2dol4tzoh3mam41rvldrs3zvp7rkbgp.png)
Total number of kilos bought = 20
A)
![x+y=20](https://img.qammunity.org/2021/formulas/mathematics/college/5mer5qz67ufzichbtam5w4f0fpvcyt3ovp.png)
Cost of mango per kg = 60
Cost of mango for
kg =
![60x](https://img.qammunity.org/2021/formulas/mathematics/high-school/8lypynzxh672adqeo4zn5xikw7ub2bbqvl.png)
Cost of atis per kg = 40
Cost of mango for
kg =
![40y](https://img.qammunity.org/2021/formulas/mathematics/college/24mgwwhh8l9iz3izdat0zw5c20hih3ffsq.png)
Total cost is: Cost of mango + Cost of atis = 1000
B) Cost function is:
![60x+40y=1000\\\Rightarrow 3x+2y = 50 ...... (2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/mmbzr3xi64frizb6bv8qnwnqco778z71la.png)
C) System of equations are:
...... (1)
...... (2)
D) Using elimination method:
Multiplying equation (1) with 2 and subtracting from (2):
![x = 10](https://img.qammunity.org/2021/formulas/mathematics/middle-school/gwot6ylqcy58ja7tb07muh9lk3ac30atr9.png)
By equation (1):
![\Rightarrow y =10](https://img.qammunity.org/2021/formulas/mathematics/high-school/ibp8i9brbcxl4vh7uqhb8rg8ct4nn4s4pm.png)
E) Putting both the values in LHS of equation (1):
10+10 = 20 = RHS
Putting both the values in LHS of equation (2):
= 50 = RHS
Yes, the result satisfies the equations.