Wilda can do the job in 4 hours ... she does 1/4 (or 0.25) of it each hour.
Karla can do it in 5 hours ... she does 1/5 (or 0.2) of it each hour.
Wilda worked alone for 1 hour ... 0.25 of the job was done before her helper
arrived. So only 0.75 of the job remained to be done together.
Working together, they accomplish (0.25 + 0.2) = 0.45 of the job in 1 hour.
How many times do they need to do 0.45 of the job in order to finish
the 0.75 of it that remains ? That's the number of hours it will take them,
working together.
0.75 / 0.45 = <em>1 and 2/3</em>
After Wilda worked alone for 1 hour and Karla came along to join her, it will
take them another <em>1 hour and 40 minutes</em> to finish the job and go for a swim.
(a+b)^7= a^7+ 7a^7b+ 21 a^6b²+ 35a^5b³+ 35 a⁴b⁴+ 21 a³b^5 + 7a²b^6 + b^7
46/287.5 = .16
.16x287.5 = 46
The answer is 16%
Answer:
N = {13, 15, 17, 19}
Step-by-step explanation:
The natural numbers greater than 11 and less than 21 are:
12, 13, 14, 15, 16, 17, 18, 19 and 20
Odd numbers are numbers that have remainders when divided by 2. Out of the numbers above, the numbers with remainders when divided by 2 are 13, 15, 17 and 19.
Since N is the set of odd natural numbers greater than 11 and less than 21,
N = {13, 15, 17, 19}
