Question

1. The sum of the third and seventh term of an arithmetic progression is 300. What is the value of the 5th term of the progression?

2. If score of boys is increased by 4 each because of which mean increases by 1.2, find the percentage of girls in the class.

3. The average of 62 numbers is 8, the average of 30 numbers is 9, and the average of last 31 numbers is 7. Find the 31st number.

Answer 1

Answer:

1 answer

t3+t7=300;t5=a+4d

Step-by-step explanation:

a+2d+a+6d=300

2a+8d=300

2 (a+4d)=300

a+4d=150