Question

In a test Freya scores 25% more marks than Eva. Eva scores 50% more marks than Dominic. In total the three children scored 140 mark. The test is out of 80. What percentage does Dominic score in the test?

Answer 1

57.8%

Explanation:

Let Eva's score = x

Freya scores 25% more marks than Eva = x + 25%

Fred score = x + 0.25

Let Dominic's score = y

Eva scores 50% more marks than Dominic = 50% + y

Eva's score: x = 0.5 + y ....equation 1

Total marks the three children scored = 140 mark

Eva's score + Fed's score + Dominic's score = 140

x + x + 0.25 + y = 140

2x + y + 0.25 = 140 ...equation 2

Substitute the value of x (equation 1) in equation 2

2(0.5+y) + y + 0.25 + y = 140

1 + 2y + y + 0.25 + y = 140

1.25 + 3y = 140

3y = 140-1.25

3y = 138.25

y = 138.25/3

y = 46.25

Dominic's score = 46.25

Eva's score = x = 0.5 + 46.25 = 46.75

Fred's score = x + 0.25 = 46.75+ 0.25 = 47

Test total =80

Percentage Dominic scoref in the test = (46.25/80) × 100 = 57.8%