The following table shows the percentage change in the consumption of electricity by five towns P, Q, R, S, T from 1986 to 1988 . If town T consumed 500,000 units in 1986, how much did it consume in 1988 ?

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Q: 114 (IAS/2001)
The following table shows the percentage change in the consumption of electricity by five towns P, Q, R, S, T from 1986 to 1988 .
If town T consumed 500,000 units in 1986, how much did it consume in 1988 ?
TownFrom 1986 to 1987 (%change)From 1987 to 1988 (%change)
P8-18
Q-1511
R69
S-7-5
T1.3-6

question_subject: 

Science

question_exam: 

IAS

stats: 

0,1,12,5,1,5,2

keywords: 

{'percentage change': [0, 0, 1, 0], 'consumption': [2, 4, 6, 10], 'electricity': [0, 0, 1, 3], 'following table': [0, 2, 1, 1], 'units': [1, 2, 4, 7]}

Option 1: 371,000 units - This is incorrect. Increases of 1.3% in 1987 and a decrease of 6% in 1988 do not result in such a low total.

Option 2: 531,100 units - This is correct. The town T consumed 500,000 units in 1986 and then it increased by 1.3% in 1987. So, 500,000 + (1.3/100)*500,000 = 506,500 units in 1987. Then, the consumption decreased by 6% in 1988, so 506,500 - (6/100)*506,500 = 531,100 units in 1988.

Option 3: 551,100 units - This is incorrect because it results from applying the percentage changes incorrectly.

Option 4: 571,100 units - This is also incorrect as it is greater than the correct answer, indicating that the consumption had been overestimated.

In this type of problem, it`s important to sequentially apply the percentage changes year by year to the previous year`s total.