Some students (only boys and girls) from different schools appeared for an Olympiad exam. 20% of the boys and 15% of the girls failed the exam. The number of boys who passed the exam was 70 more than that of the girls who passed the exam'. A total of 90 students failed. Find the number of students that appeared for the exam.

If the average marks of three batches of 30, 50 and 70 students is 55, 70 and 70 respectively, then the average marks of all the students is:

The average of 5 consecutive even numbers is A. If next 5 even numbers are also included, then what is the average of these 10 numbers?

Average weight of 10 persons is 40 kg. A new person join the group and average weight of 11 persons becomes 42 kg. What will be the weight of new person?

The average of 10 observations is 21. A new observation is included and the average of these 11 numbers is 1 less than the prevoius average. The 11^th observation is____

The mean of five numbers is 18. If one number is excluded, their mean is 16. The excluded number is:

A shopkeeper purchases 20000 units of a product at ₹1 each, 15000 units at ₹1.15 each and 5000 units at ₹2 each. What is the weighted average price of one unit? Correct to two decimal places)

A supermarket has sales of ₹1,48,500, ₹2,00,000, ₹1,64,000, ₹1,88,600 and ₹2,40,400 in 5 consecutive months. How much sales should the supermarket have in the 6th month so that the average sales for these 6 months become ₹1,88,300?