Let's let the weight of a large box be L, and the weight of a small box be S.
We know that 5 large boxes and 3 small boxes is 120kg, so:
5L + 3S = 120
We also know that 7 large boxes and 9 small boxes is 234kg, so:
7L + 9S = 234
You can multiply the first equation by 3 to get:
15L + 9S = 360
See how now both equations have 9S? We can now subtract one from the other:
(15L+9S) - (7L+9S) = 360-234
8L = 126
L = 15.75
Now sub this value back into an equation:
(5x15.75) + 3S = 120
3S = 41.25
S = 13.75
Double check these values
(7x15.75) + (9x13.75)
= 110.25 + 123.75
=234, which is consistent with above.
So a large box is 15.75kg, and a small box is 13.75kg.
Hope this helped
Given:
Total number of students = 27
Students who play basketball = 7
Student who play baseball = 18
Students who play neither sports = 7
To find:
The probability the student chosen at randomly from the class plays both basketball and base ball.
Solution:
Let the following events,
A : Student plays basketball
B : Student plays baseball
U : Union set or all students.
Then according to given information,
We know that,
Now,
It means, the number of students who play both sports is 5.
The probability the student chosen at randomly from the class plays both basketball and base ball is
Therefore, the required probability is .
Answer:
6.7 * (10^7) = 67 000 000