Question

The temperature at noon is 75 Fahrenheit. The temperature drops 3 degrees every half hour. What is the temperature at 4 p.m.

Answer 1

75 - 3 every half hour so minus 6 every hour,
between noon and 4pm, there are 4 hours
4*6 = 24
75 - 24 = 51

Answer 2

Noon is 12 pm.

Temperature drops by 3° every 30 minutes.

There are 240 minutes in 4 hours.

So, in 4 hours or 240 minutes, the temperature dropped by 24°.

By 4 pm, the temperature is 51°F.