1tickets decreased from 9000 to 8500 2a 17000 bicycle decrea

1)tickets decreased from $90.00 to $85.00

2)a $170.00 bicycle decreased to $155.00

there are 2 questions.

please help me find the percent of decrease for each of the following items.

Solution

Both of these are simple percentage problems. Your percentage formula is, as always:

p/w=%/100

where the part of the whole is equal to the percentage over 100.

So in this case, your part for number 1 is $5 (the amount decreased) and your whole is $90. Your percentage is unknown, so let\'s call that X. So your re-written formula should be:

$5/$90 = X/100

This is a proportion, so we can cross-multiply, so:

$5 x 100 = 500

$90 x X = 90X

So now we have 90X = 500.

In order to isolate X, we need to divide 90 from both sides.

90X / 90 = X

500 / 90 = 5.56

So, X = 5.56, and therefore the price decreased by 5.56%.

For number 2, your part is $15, your whole is $170, and again your percentage is unknown, X.

$15/$170 = X/100

So again, we cross-multiply, and get:

$15 x 100 = 1500

$170 x X = 170X

And therefore,

1500 = 170X

Now we isolate X by dividing out the coefficient from both sides.

170X / 170 = X

1500 / 170 = 8.82

Therefore, X = 8.82%, your percentage of decrease.