Name:    Lesson 7: Solving Problems by Working Backwards

1.

Conner is lifting weights.  Each week he lifts 2 more kg than the previous week.  If Conner lifted 15 kg on the 7th week, what was his starting weight?
 a. 1kg b. 2kg c. 3kg d. 4kg

2.

Claire is having a garage sale.  Every hour she marks down toys by \$0.25.  After the 8th hour, the toys cost \$5.50.  What was the starting price of the toys?
 a. \$6.75 b. \$7.00 c. \$7.25 d. \$7.50

3.

Grayson earned \$45.00 in one day.  Every hour he earns \$3.00 more, but he started at base dollar amount.  He worked for 8 hours.  What was that dollar amount Grayson started with?
 a. \$20.00 b. \$21.00 c. \$22.00 d. \$23.00

4.

Kaylee is stacking boxes.  Each hour Kaylee stacks 8 boxes.  After 7 hours, Kaylee has stacked 86 boxes.  How many boxes were stacked before Kaylee began?
 a. 20 b. 25 c. 30 d. 35

5.

Each hour Sean collects \$8.00 for charity. After 9 hours, Sean has collected \$172.00.  Sean received a large donation from one person at the beginning of his day.  How much money did the donor give?
 a. \$80.00 b. \$90.00 c. \$100.00 d. \$120.00

6.

Brayden and his brother are shovelling driveways.  It takes Brayden 15 minutes to shovel one driveway.  If Brayden shovelled for 3 hours and there were 21 driveways shovelled, how many driveways did his brother shovel?
 a. 7 b. 8 c. 9 d. 10

7.

Jackie counted cars on a busy road.  Each hour 75 cars went by.  At the end of her session, Jackie had counted a total of 450 cars.  How many hours did Jackie count for?
 a. 3 b. 4 c. 5 d. 6

8.

 a. 0 b. +5 c. -5 d. +10

9.

When you subtract (+6) then add (+12) to a number, the total sum is 0.  What number did you start with?
 a. -6 b. +6 c. 0 d. +12

10.

When you add (-13) then subtract (-13) the answer is 20.  What was the starting number.
 a. -13 b. +20 c. 0 d. -20