Answer:
81
Step-by-step explanation:
square root of 729= 9
9×9=81
<h2>Answer:</h2>
Number of biology textbooks sold: 257 textbooks
Number of psychology textbooks sold: 181 textbooks
<h2>Explanations:</h2>
Let the total number of biology textbook sold be "a"
Let the total number of psychology textbook sold be "b"
If a textbook store sold a combined total of 438 biology and psychology textbooks in a week, then:
a + b = 438 ................... 1
If the number of psychology textbooks sold was 76 less than the number of biology textbooks sold, then;
b = a - 76 ...................... 2
Substitute equation 2 into 1
a + (a-76) = 438
a + a - 76 = 438
2a = 438 + 76
2a = 514
a = 514/2
a = 257 biology textbooks
From equation 2;
b = a - 76
b = 257 - 76
b = 181 psychology textbooks
Number of biology textbooks sold: 257 textbooks
Number of psychology textbooks sold: 181 textbooks
Fairly straightforward question. She works 30 days and is late 80% or 0.8
We can model our equation
Num days late = late percentage * num working days
Basically fine portion of working days that she was late.
Num days late = 0.8 * 30=24
So Deborah was late 24 out of 30 working days. Would appreciate a brainliest
Answer:
11.95 dollars
Step-by-step explanation:
Cost of one LED bulb = 6.95 dollars
Cost of changing one bulb = 3 dollars
Life of each bulb = 5 years.
In 10 years, only one time after 5 years the bulbs would have been changed
Hence cost of 100 lamps = 695 and
cost of changing once = 500
Total cost = 1195 dollars for 11 years
Divide this by 10 years to get average cost per year
Cost of 100 lamps per year = 1195/100 = 11.95 dollars
