Question

Duane recorded the temperature outside his window one morning. On the second day, the temperature went up 7 degrees. On the third day, the temperature went down 10 degrees. On the fourth day, the temperature went down 6 degrees, and it was 1°F. What was the temperature on the first day?

Answer 1

The temperature on the first day was 10 °F.

Explanation:

Let's find the temperature in every single step starting from the fourth day:

`T_(4) = T_(3) - 6 F = 1 F`

`T_(3) = 1 F + 6 F = 7 F`

Then, the temperature of the third day was 7 °F

On the third day:

`T_(3) = T_(2) - 10 F = 7 F`

`T_(2) = 7 F + 10 F = 17 F`

Hence, the temperature on the second day was 17 °F.

Now, on the second day:

`T_(2) = T_(1) + 7 F = 17 F`

`T_(1) = 17 F - 7 F = 10 F`

Therefore, the temperature on the first day was 10 °F.

I hope it helps you!