Question #47e8d

2 Answers
Jan 23, 2018

28%

Explanation:

If The temperature is 100,
100 decreased by 60%=40 Degrees
80% of 40: 32
40+32=72
100-72=28
28%

Jan 23, 2018

See a solution process below:

Explanation:

First, let's call the initial temperature: t

If it first decreased by 60% then the new temperature (t_n) would be:

t_n = t - 60/100t

t_n = 100/100t - 60/100t

t_n = (100/100 - 60/100)t

t_n = 40/100t

t_n = 4/10t

Then if this new temperature increase by 80% the final temperature (t_f) would be:

t_f = t_n + 80/100t_n

However, we can substitute 4/10t for t_n giving:

t_f = 4/10t + (80/100 xx 4/10t)

t_f = 4/10t + 320/1000t

t_f = 400/1000t + 320/1000t

t_f = 720/1000t

t_f = 72/100t

Therefore, the final temperature is 72% of the original temperature.

Or, in total the temperature decreased by 28%