Answer:
1st, 3rd and 4th
Step-by-step explanation:
Only 2nd is false
Answer:
£1000, £1400
Step-by-step explanation:
Sum the parts of the ratio 5 + 7 = 12 parts
Divide the amount by 12 to find the value of one part of the ratio.
£2400 ÷ 12 = £200, thus
5 parts = 5 × £200 = £1000
7 parts = 7 × £200 = £1400
((7 + 5)^2) / (4 * 3 + 9) =
(12^2) / (12 + 9) =
144 / 21 reduces to 48/7 or 6 6/7
There is no such thing as a "kilowatt per hour". If that's actually what the question says, then it's a defective question, and you should put it away before it makes you any more confused.
A 120 watt light bulb uses exactly 0.12 kilowatt when it's turned on.
In one hour, it uses
(0.12 kilowatt) x (1 hour) = 0.12 kilowatt-hour of energy.
If energy costs $0.20 per kilowatt-hour, then the cost is
(0.12) x (0.20) = 2.4 cents. (0.024 dollar)
