7)A city has an assessed valuation of $8,000,000. The rate for school taxes is 60 cents per $100 valuation. If all but 4% of the school taxes were collected, how many dollars were still owed?

The amount that should have been collected is

[ 8000000 / 100] * .60 = $48000

If all but 4% have been collected, then .04 * 48000 = $1920 is still owed

8)On Tuesday, a radio store reduces all of its prices by 20% from what they were on Monday.

On Wednesday, the store again reduces all of its prices by some percentage from what they were on Tuesday. If the resulting price of a radio is half of the original Monday price, then by what percentage did the store reduce its prices from Tuesday to Wednesday?

Call Monday's price, P

Tuesday's price must just be .80P [ 20% reduction]

Call Wednesday's price reduction ( 1 - R)

So...we have that

Tuesday's price * Wednesday's reduction = (1/2)P

(.80)P *( 1 - R) = (1/2)P divide through by P and note that 1/2 = .50

.80 (1 - R) = .50 divide both sides by .80

1 - R = .50/.80

1 - R = 5/8

1 - 5/8 = R

3/8 = R = .375 = 37.5% = the reduction from Tues. to Wed.

Proof of this...let Monday's price = 100

Tuesdays price = .80 * 100 = 80

Wed price = 80 (1 - R) = 80 (1 - .375) = 50 = half of Mon. price