Question

Arathi took three examination in a year. The marks obtained ny her in the 2 and 3 rd examination more than 5 and 10 respectively rhan in 1 st examination. If her mark is at least 80. Find the minimum mark that she should get in first examination ?

Answer 1

let she get X marks in first examination.
then she will get X+5 in second andx+10 in third.
now, X+(X+5)+(X+10)=80
3x+15=80
3x=80-15
3x=65
X=65/3

Answer 2

Answer:

let the marks of 1st exam be x

so marks of 2nd exam be x+5 and 3rd exam be x+10

average>80

Step-by-step explanation:

x+(x+5)+(x+10)/3>80

3x+15>240

3x>240-15

x>225/3

x>75

the minimum mark he should score is 75