Direction : What should come in place of the question (?) in the following question.

8934 – 3257 + 481 = ? + 2578

Shyam can complete a task in 12 days by working 10 hours a day. How many hours a day should he work to complete the task in 8 days?

If for two real constants a and b the expression ax³+3x²-8x+b is exactly divisible by (x+2) and (x-2), then 

What least value must be assigned to ‘*’ so that the number 63576 * 2 is divisible by 8?

A bus can cover a distance of 420 km in 7 hours. How much will the speed have to be increased to cover this distance in 6 hours?

How many natural numbers divisible by 7 are there between 3 and 200? 

Direction: Study the following graph carefully and answer the questions that follow:
The graph given below represents the number of users of two broadband services A and B across 5 cities P, Q, R, S and T.

What is the difference between the total number of users of brand A and B together in City R and the total number of users of brand A and B together in City P?

Two trains start from P and Q respectively and travel towards each other at a speed of 50 km/hour and 40 km/hour respectively. By the time they met the first train had travelled 100 km more than the second. Find the distance between P and Q?