Twenty girls and y boys sat on an examination. The mean m...
Twenty girls and y boys sat on an examination. The mean marks obtained by the girls and boys were 52 and 57 respectively. if the total score for both girls and boys was 2750, find y.
51
48
30
25
18
Correct answer is C
Let the total score for the girls and the boys be A and B respectively.
A20=52⟹A=52×20
A = 1040
By=57⟹B=57y
1040 + 57y = 2750
57y = 2750 - 1040
57y = 1710
y = 171057
y = 30
Given that (2x - 1)(x + 5) = 2x2 - mx - 5, what is the value of m ...
What is the product of 2751(3)-3 and (1)−15?...
If a car travels 120km on 45 litres of petrol, how much petrol is needed for a journey of 600km? ...
If the mean of five consecutive integers is 30, find the largest of the numbers ...
For what value of x is the expression x - 5/x2 - 2x - 3 not defined?...