The temperature at noon was −3C. By 10 P.M.on the same day the temperature decreased by 5.4. What was the temperature at 10 P.M.?

A−8.4C B−5.4C
C−2.4C D1.6 C

-3 - 5.4 = -8.4

To find the temperature at 10 P.M., we need to subtract 5.4°C from the temperature at noon (-3°C).

-3°C - 5.4°C = -8.4°C

Therefore, the temperature at 10 P.M. was -8.4°C.

So the answer is A) -8.4°C.

To find the temperature at 10 P.M., we need to subtract the decrease of 5.4°C from the temperature at noon, which was -3°C.

To do this, we use the formula:
Temperature at 10 P.M. = Temperature at noon - Decrease in temperature

Substituting the given values:
Temperature at 10 P.M. = -3°C - 5.4°C

Now, subtracting -3°C from -5.4°C:
Temperature at 10 P.M. = -3°C + (-5.4°C)
Temperature at 10 P.M. = -8.4°C

Therefore, the temperature at 10 P.M. was -8.4°C.
Hence, the answer is option A: -8.4°C.