Find the area of the shaded region.

Step-by-step explanation:

Remark

The method of finding the area of the ring is to find the area of the outer ring and subtract the area of the hole in the middle.

Outer ring

r = 10 + 4  = 14 inches

Area = pi * r^2

Outer ring area = pi * 14^2

Outer ring area = 196 pi

Inner hole

Area unshaded part = pi * r^2

r = 10

Area = pi * 10^2

Area = 100 pi

Area of the shaded part

area of the shaded part = outter circle area - inner circle area

outter circle area = 196 * pi

inner circle area = 100 pi

Area of the shaded part = 196 pi - 100 pi

Area of the shaded part = 96 pi

pi = 3.14

Area of the shaded part = 96 * 3.14

Answer area of the shaded part = 301.44

Answer area of the shaded part = 301.4 rounded to the nearest tenth

The second problem is done exactly the same way. Only the numbers have been changed. I will give you the answers to the main part of the problem and you can try and get what I got. If we disagree, be preparred to tell me what you got so I correct mine if it is wrong.

Outter Radius = 18 + 8 = 26

Area of outter circle =  pi * 26^2

Area of outter circle =  676 pi

Inner Circle area hole = pi * 18^2

Inner Circle area hole = 324 pi

Area of the shaded part = outter circle - inner circle

Area of the shaded part = 676 pi - 324 pi

Area of the shaded part = 352 pi

pi = 3.14

Area of the shaded part = 352 * 3.14

area of shaded part rounded to 1 decimal place = 1105.3

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.