The weather has been very unpredictable so far this summer, so Elsie’s teacher has asked the children to investigate. Elsie’s part of the project is to record the temperature each day.
Elsie recorded the temperature on Wednesday, Thursday and Friday.
Between Wednesday and Thursday the temperature increased by 20%.
Between Thursday and Friday the temperature decreased by 40%.
Between Wednesday and Friday the temperature decreased by x%.
Work out the value of x.
Answer:
Let the temperature on Wednesday = T
Temperature on Thursday = T increased by 20% so equals 1.2T
Temperature on Friday = 1.2T decreased by 40% so equals 1.2T x 0.6 = 0.72T
Therefore the temperature on Friday equals 72% of the temperature on Wednesday
x = 100 – 72 = 28% decrease