Find the sum of 2x terms of the series ( 1² - 2² + 3² - 4² + ___ ) 

Find the greatest value of (a + b) such than an 8-digit number 4523a60 b is divisible by 15.

Directions: Find the wrong number in the following number series:

141, 156, 147, 162, 153, 165, 159

If a shopkeeper buys 2 oranges for Rs.5 and sells 3 for Rs.7 only, then what percentage of loss and loss did he gain?

Find the greatest value of k for which the 6-digit number 24312k is divisible by 6.

The sum of the two - digit number is 6 and the number and its flip (digits written in reverse order) both are multiples of 3. If the difference between them is 36, then which of the following is the required number and its flip? 

If 30% of a = b, then b% of 50 is the same as:

Find the solution of 5x-7=12?