<u>Solution-</u>
From the figure,
AE = 2.4
EB = 2.8
BC = 11.7
Area of rectangle 1 = 8.68 sq.in

(∵ sides of the rectangle 2)
Area of Triangle 1 = 6.48 sq.in


(∵ sides of the rectangle 1)


(∵ sides of the rectangle 2)



The area of Rectangle 2,

The area of Triangle 2,

The area of the whole figure = Area of Triangle 1 + Area of rectangle 1 + Area of Triangle 2 + Area of rectangle 2
= 6.48+8.68+8.82+6.44=30.42 sq.in
So exactly it would be 39.48, but do you want me to round to a specific ten?
<span>6 km × 1 hour/(b-4 km) = 12 km × (1 hour/(b+4 km)
6/(b-4) hours = 12/(b+4) hours
6(b+4) = 12(b-4)
6b + 24 = 12b - 48
72 = 6b
b = 12
The boat's speed in still water is 12 km/hour.</span>
The first and the last are correct.