Answer:
20 students
Step-by-step explanation:
If the class decreased by 15%, the students that she has now (17) represents a percentaje of:
100% - 15% = 85%
so<u> the 17 students are 85% of what she had</u>:
Students Percentage
17 ⇒ 85%
and we are looking for how many students she had 2 years ago, thus we are looking for the <u>100%</u> of students (the original number of studens). If we represent this number by x:
Students Percentage
17 ⇒ 85%
x ⇒ 100%
and we solve this problem using the <u>rule of three</u>: multiply the cross quantities on the table( 17 and 100) and then divide by the remaining amount (85):
x = 17*100/85
x = 1700/85
x=20
2 years ago she had 20 students
Answer:
increase = 37.38 cm²
You'd like the first way because it took less effort and less chance of a miscalculation.
Step-by-step explanation:
first way:
(just work with the difference in height)
(0.7 x 8.7 x 2) + (0.7 x 18 x 2) = 37.38 cm²
second way:
old total lateral surface area = (31 x 8.7 x 2) + (31 x 18 x 2) = 1655.4
new total lateral surface area = (31.7 x 8.7 x 2) + (31.7 x 18 x 2) = 1692.78
increase = 1692.78 - 1655.4 = 37.38 cm²
Answer:
773 and 869 and 703 on any day
Let's find the least possibilities:
First number: 6
Second number: 8
Third number: 10
6 + 8 + 10 = 24
Now we can see that we are still missing 31 - 24 = 7.
7 can be gained by adding 3 and 4, so:
First number: 6 + 3 = 9
Second number: 8 + 4 = 12
Third number: 10
9 + 12 + 10 = 31
