Out of 120 applications for a post, 70 are male and 80 have a driver's license. What is the ratio between the minimum to maximum number of males having driver's license?

Here's a brief explanation:

1. Identify the total groups:

   • Total applicants = 120
   • Males = 70
   • Females = 120 - 70 = 50
   • People with driver's license (DL) = 80
   • People without driver's license (NDL) = 120 - 80 = 40

2. Calculate the minimum number of males with DL:

   • To minimize males with DL, we must maximize the number of females with DL.
   • The maximum number of females with DL can be 50 (since there are only 50 females).
   • If 50 females have a DL, then the remaining people with DL must be male.
   • Minimum males with DL = Total DL - Max Females with DL = 80 - 50 = 30.
   • (Alternatively: To minimize males with DL, maximize males without DL. The maximum number of people without DL is 40. If all these 40 are males, then males without DL = 40. So, males with DL = Total Males - Males without DL = 70 - 40 = 30.)

3. Calculate the maximum number of males with DL:

   • The number of males with DL cannot exceed the total number of males (70).
   • The number of males with DL cannot exceed the total number of people with DL (80).
   • Therefore, the maximum number of males with DL = minimum(70, 80) = 70.

4. Form the ratio:

   • Ratio of minimum to maximum males with DL = 30 : 70
   • Simplifying the ratio = 3 : 7

5. Conclusion: The ratio is 3 to 7, which corresponds to option C.

The final answer is C.