Weighted Averages Review

If Brooklyn has 49 coins worth $3.75 in all dimes and nickels, how many dimes does she have?

Answer explanation

If you have 49 nickles and dimes then for the # of coins in the table one is x and the other is 49-x

x+y=49 then solve for y

y=49-x

Tags

CCSS.8.EE.C.7B

A car started out for New Jersey traveling 50mph, three hours later a second car traveling in the same direction left traveling 75mph. How long will it take the second car to over take the first car?

Answer explanation

The car leaving later should have a higher speed

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.CED.A.2

CCSS.HSA.REI.B.3

If Yasmin mixes 10 pounds of Oreos worth $2.50 per pound with how many pounds of chocolate chip cookies worth $2.00 to make a snack mixture that cost $2.40 per pound?

answer is in decimal form

Answer explanation

2.50 *10

2.00*x

2.4 *10+x

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.CED.A.2

CCSS.HSA.CED.A.3

CCSS.HSA.REI.B.3

CCSS.HSA.SSE.A.1

Gabriel's team bus drove from Somerset to New Hampshire at an average rate of 68 mph and returned at an average rate of 85 mph. Find the time going if the time returning was one hour less than the time going.

Answer explanation

going 68*5

returning 85*(x-1)

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.CED.A.2

CCSS.HSA.CED.A.3

CCSS.HSA.REI.B.3

Two trains start at the same time from towns 900 miles apart and meet 6 hours later. If the average rate of one train is 10 mph faster than the other find the rate of the slower train.

Answer explanation

FASTER (x+10)6=SLOWER (X)6

Tags

CCSS.HSA.CED.A.1

Mrs. Thibault is selling tickets to the football game. It cost $5 for adult tickets and $2 for student tickets. If I sold a total of 720 tickets and take in $2940 at the end of the night, how many adult tickets did I sell?

Answer explanation

number of tickets

one is x and the other is 720-x

x+y=720

so y=720-x

Tags

CCSS.8.EE.C.8C

Madilyn's health food store sells a mixture of cranberries and granola.

Cranberries sell for $6 and granola sells for $4. How many pounds of cranberries should be mixed to make 20 pounds worth $5?

Answer explanation

the amount is a total so one is x and the other is 20-x

Tags

CCSS.8.EE.C.8C