6/9 and 12/21
i think this is the answer your looking for
To find the mean you must add up all the numbers and divide by how many there are:
35 + 60 + x
_________ = 70
3
35 + 60 + x = 210
x = 65
He must score at least a 65 for a 70 average.
Given:
child = 2 forks
adult = 5 forks
total number of forks = 2992
total number of people = 764
c + a = 764
2c + 5a = 2992
find the value of c using the 1st equation.
c = 764 - a
substitute c in the 2nd equation by its value
2c + 5a = 2992
2(764-a) + 5a = 2992
1528 - 2a + 5a = 2992
1528 + 3a = 2992
3a = 2992 - 1528
3a = 1464
3a/3 = 1464/3
a = 488
c = 764 - a
c = 764 - 488
c = 276
child = 276 ; adult = 488
2c + 5a = 2992
2(276) + 5(488) = 2992
552 + 2440 = 2992
2992 = 2992
