Math retake

Bob runs 6 laps on the track every 9 minutes. At this rate, how many minutes will it take him to run 18 laps? 6/9 = 18/x

Hint: 6 times what gives you 18 laps?

• 2.7

• 27

• 270

• 355

Reduce 30 birds per 5 cages.

Hint: birds per cages is 30/5

• 1/6

• 6/1

• 6/24

• 142456/245

Bob bought a pack of 36 water bottles for 80 RMB. What did each water bottle actually cost him?

• 2.50

• 2.22222

• 2

• 1.66666

There are 8 buses and 160 students. What is the ratio of students to buses? Hint: STUDENTS to BUSES. Not buses to students.

• 25/2

• 1/20

• 20/1

• a few buses a lot of students

10.4 x -0.5 =

• - 5.2

• 5.2

• 4.7

• 470

x/3 = 1/4 what is the first step we should take?

Hint, multiplying 1/4 to each side does NOT help us to isolate x

• randomly guess

• multiply each side by x

• multiply each side by 1/4

• multiply each side by 3 or 3/1

-23.4 - 3.4 =

HInt: the answer is NOT: -20

• -20

• -26.8

• 20

• 26.8

3/10 - -1/4 =

Hint: 3/10 + 1/4 =

• 11/20

• -11/20

• 1/20

• -1/20

1/2 - (-2/5)

hint: a subtraction sign and a negative is a positive operation

double hint for people who have missed this question twice already: 1/2 + 2/5 =

• - 9/10

• 9/10

• 1/10

• -1/10

6/15 as a decimal =

• .4

• .42

• 1.4

• 4