RRRR. . . Math! =[?

Question

Question 3:
Robert drove to the mall, which is twelve kilometers away. He left at 2:57 and arrived at the mall at 3:19. What was his average driving speed?





Remember to convert to hours!
Round to a whole number
kph
Question 4:
If the base of a rectangle is 17.8 cm and the area is 357.78 cm2, what is the height of the rectangle?





Enter a decimal
cm
Question 5:
If the area of a rectangle is 646.84 mm2 and the height is 31.4 mm, what is the perimeter of the rectangle?





mm
Question 6:
If the area of a parallelogram is 391 mm2 and the height is 23 mm, what is the length of the base?





mm

Answer 1

3. 12 km in 22 minutes
22/60 = 0.37 hours
12 km/0.37 hours = 32.43 km/hour
nearest km is 32 km/hr

4. A=base x height
357.78=17.8 x h
h= 357.78/17.8
h=20.1 cm

5. A=b x h
646.82= 31.4 x b
b= 20.6 mm
P= 2b + 2h
P=2(31.4) + 2(20.6)
P=104 mm

6. A = b x h
391 = 23 x b
b=17 mm

Answer 2

Question 3 is answered using distance = rate (speed) * time (minutes)

d = r*t
12=r*22
12/22=r
r=0.5454....

r right now is in km/min, we want km/hr so we multiply r by 60

r=32.7272... rounded to the nearest whole number gives us

r = 33 km/hr

Question 4

The area of a rectangle is height * base

A = h*b

357.78 = h*17.8
357.78/17.8 = h
h = 20.1

Question 5

Using the same formula to find the missing side (perimeter is simply all the sides added together)

A = h*b
646.84 = 31.4*b
646.84/31.4 = b
b = 20.6

Now add up all the sides to find the perimeter

31.4+31.4+20.6+20.6 = 104

Question 6

The area of a parallelogram is base*height (look familiar)

A = b*h
391 = b*23
391/23 = b
b = 17

Hope this helped.
10 pts best answer?

Answer 3

Will do work but will tell you how.
3. Rate x time = distance 22 min is 11/30 of an hour. So r x 11/30 = 12. solve for r.

4. base x height = area. so area / base = height. 357.78/17.8

5.base + height x 2 = perimeter. so 646.84/31.4=base

6. same thing.