E Math Prelim Percentage Qn

Nathpoop SG

The price of tea has increased by 25% calculate the percentage of tea consumption that is to be decreased if there is no change in the amount spent on tea for a household.

How do i solve this question?

dkcx SG

The price of tea has increased by 25% calculate the percentage of tea consumption that is to be decreased if there is no change in the amount spent on tea for a household.

How do i solve this question?

Should be 20% i think.

Cost of tea gone up so you get 125% of the cost. To bring down the cost back to 100%, you need reduce it by 25% so 25/125 is 20%.

caleb_chiang SG

erm... TS really dun know?

Nathpoop SG

erm... TS really dun know?

I don't understand the question, don't get it.

wee_ws SG

The price of tea has increased by 25% calculate the percentage of tea consumption that is to be decreased if there is no change in the amount spent on tea for a household.

How do i solve this question?

Hi,

Let x be the price of tea and y be the consumption.

Then the amount spent on tea is given by xy.

Since the price of tea has increased by 25%, the new price of tea is 5/4 x.

For the amount spent to remain at xy, we will then need the consumption to drop to 4/5 y.

Thus, the consumption has to be decreased by 20%.

Thanks!

Cheers,
Wen Shih