Final answer:
Mr. Janes will take 10 hours to write 25 tests.
Step-by-step explanation:
To find out how long it will take Mr. Janes to write 25 tests, we can set up a proportion using the information given. If he can write 10 tests in 4 hours, we can write the proportion as:
10 tests / 4 hours = 25 tests / x hours
Using cross multiplication, we can solve for x:
10x = 100
x = 10 hours
Therefore, it will take Mr. Janes 10 hours to write 25 tests.