In an examination,Dada scored x% in maths,50% in science and 70% in English studies.if his mean score for the three subject was 55%, find x
let x be the unknown
(50+70+x)/3=55
50+70+x=(55x3)
50+70+x=165
transpose 50 and 70 to the other side and let x remain
x= 165-50-70
x=45%
check:
if each test is 100 items..then..
50% of 100 for science=50
70% of 100 for english=70
45% of 100 for math= 45
and mean is the average of the three subj..then..
(50+70+45)/3=55
Please,Can I get your link?
The sum of 6 and one-third of x is one more than twice x. find x
Well, let's use our math skills to solve this problem! Now, we know that Dada's mean score for the three subjects is 55%. So, we can create the equation:
(x + 50 + 70) / 3 = 55
Simplifying this equation, we get:
(x + 120) / 3 = 55
Cross multiplying, we have:
x + 120 = 165
Subtracting 120 from both sides, we find:
x = 45
So, Dada scored 45% in math.
To find the value of x, we need to use the concept of weighted average. Let's break down the problem step by step.
Step 1: Assign weights to each subject based on their importance. Since we are trying to find the mean score, we can consider each subject equally important, so each subject will have a weight of 1.
Step 2: Calculate the weighted average using the formula:
Weighted Average = (Weight1 * Score1 + Weight2 * Score2 + Weight3 * Score3) / (Weight1 + Weight2 + Weight3)
In this case, the scores are as follows:
Maths score = x%
Science score = 50%
English score = 70%
Using the weights of 1 for each subject, the formula becomes:
55% = (1 * x% + 1 * 50% + 1 * 70%) / (1 + 1 + 1)
Step 3: Simplify the equation:
55% = (x% + 50% + 70%) / 3
Multiplying both sides of the equation by 3:
165% = x% + 120%
Step 4: Solve for x:
165% - 120% = x%
45% = x%
Therefore, Dada scored 45% in Maths.