Question

write true or false in each blank.

1. 5,639 watts equals 5.639 kilowatts.
2. 18 sq. ft. = 6 sq. yd.
3. the area of a 6 ft. by 9 ft. rectangle is 15 sq. ft.
4. 3.5 kilowatts equals 350 watts.
5. 2% of $127,500 is $2,500.
6. the electric meter dials read 61,465 kwhr.
7. 7.3¢ equals $.073.
8. 5,300 divided by 1,000 equals 53.
9. an electrician who works 6½ hours at $37.50 per hour earns $243.75.
10. 932 kwhr at 6.9¢ per kwhr costs $643.08.

Explanation:

Step1: Convert watts to kilowatts

Since \(1\) kilowatt \( = 1000\) watts, to convert \(5639\) watts to kilowatts, we divide by \(1000\): \(5639\div1000 = 5.639\) kilowatts.

Step2: Convert square - feet to square - yards

Since \(1\) square - yard \(=9\) square - feet, to convert \(18\) square - feet to square - yards, we divide by \(9\): \(18\div9 = 2\) square - yards, not \(6\) square - yards.

Step3: Calculate the area of a rectangle

The area of a rectangle \(A=l\times w\), where \(l = 9\) ft and \(w = 6\) ft. So \(A=9\times6=54\) square - feet, not \(15\) square - feet.

Step4: Convert kilowatts to watts

Since \(1\) kilowatt \( = 1000\) watts, \(3.5\) kilowatts \(=3.5\times1000 = 3500\) watts, not \(350\) watts.

Step5: Calculate \(2\%\) of \(\$127500\)

\(2\%=\frac{2}{100}=0.02\), then \(0.02\times127500 = 2550\), not \(2500\).

Step6: Read the electric meter dials

For electric meter dials, we read the number as the pointer passes. The first dial: \(6\), second dial: \(1\), third dial: \(4\), fourth dial: \(6\), fifth dial: \(4\). So the reading is \(61464\) kwhr, not \(61465\) kwhr.

Step7: Convert cents to dollars

Since \(1\) dollar \( = 100\) cents, \(7.3\) cents \(=\frac{7.3}{100}=0.073\) dollars.

Step8: Calculate \(5300\div1000\)

\(5300\div1000=\frac{5300}{1000}=5.3\), not \(53\).

Step9: Calculate the electrician's earnings

The electrician works \(6\frac{1}{2}=\frac{13}{2}\) hours at \(\$37.50\) per hour. Earnings \(E = 37.50\times\frac{13}{2}=37.50\times6.5 = 243.75\).

Step10: Calculate the cost of electricity

\(932\) kwhr at \(6.9\) cents per kwhr. First, \(6.9\) cents \(=0.069\) dollars. Cost \(C=932\times0.069 = 64.308\), not \(643.08\).

Answer:

1. True
2. False
3. False
4. False
5. False
6. False
7. True
8. False
9. True
10. False