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

Answer:

The temperature on the first day was 10 °F.

Step-by-step 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!