A scientist builds a Mars rover that can travel 4.9 centimetres per second on flat ground if the rover continues at the the same rate how many cemeteries will it travel in 15 1/2 seconds

The answer is in the image 

The answer is in the image 

The solution is in the following image

The answer is in the image 

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The answer is in the image 

The answer is in the image 

Area of rectangle= L*b

here,

L=12.4 cm

b= 8.8 cm

A= L*b

= 12.4 * 8.8 = 109.12 cm^2

Cost before sale tax=$46.00

Cost after including tax=$48.76

Sale tax=$48.76-46.00

=$2.76

we know,

sale tax=((sales tax rate)/100) * cost before sale tax

2.76=((sales tax rate)/100) *46.00

sale tax rate=(2.76*100)/46

                   =276/46

                    =6%

There fore sales tax rate=6%

We can put the numbers in ascending order-

36, 38, 39, 39, 40, 47, 48, 51

Range=max-min

          =51-36

          =15