Final answer:
The number of bags of lychee and mango cannot be determined based on the given information.
Step-by-step explanation:
To find the number of bags of lychee and mango, we need to solve the system of equations:
Let x be the number of bags of lychee and y be the number of bags of mango.
From the given information:
- x + y = 28
- 1.5x + 1.5y = 42
We can solve this system of equations by substitution or elimination method. Using the substitution method:
From equation (1): x + y = 28, we can express x as x = 28 - y.
Substituting this value of x into equation (2): 1.5(28 - y) + 1.5y = 42.
Simplifying the equation: 42 - 1.5y + 1.5y = 42.
Canceling the y terms: 42 = 42.
This means the system of equations has infinitely many solutions, and any combination of bags of lychee and mango whose sum is 28 will work. Therefore, we cannot determine the exact number of bags of lychee and mango based on the given information. So, none of the given options (a), (b), (c), or (d) is correct.