Answer:
Original number 26.
Step-by-step explanation:
xy - two-digit number
1) x + y = 8
2) Original two-digit number can be written as
10*x + y
3) If the digits interchanged yx,
then the new number can be written as
10*y + x
4) Double the original number is
2*(10*x + y)
5) New number is 10 more than double the original number
(10*y + x) - (2*(10*x + y)) = 10
6) Now we have the system of 2 equations:
x + y = 8
(10*y + x) - (2*(10*x + y)) = 10 -----> 10y + x - (20x + 2y) = 10 ---> 8y - 19x = 10
x = 8 - y
8y - 19(8 - y) = 10
8y - 152 +19y = 10
27y = 162
y = 6
x = 8 - y = 8 - 6 = 2
x = 2
So, x =2, y = 6.
Original number 26.
Check:
Original number 26.
New number 62.
Double of the original number = 2*26= 52.
New number is 10 more than double the original number :
62 - 52 = 10 True
Answer:
1/12
Step-by-step explanation:
You are close but 1/27 includes people who did not study but still passed. If you want a singular value you should look at the value for the for only the people who studied even if they passed.
Percent change = (new - old)/old * 100
(6/7 - 3/7)/(3/7) * 100
3/7 * 7/3 * 100
1 * 100
100%
Answer:
4
Step-by-step explanation:
3x2 is 6
2-4 is -2
6-2 is 4
