Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd letters from the given alternatives.

Find the Greatest Common Factor of 280 and 144.

30% discount is offered on an item. By applying a promo code the customer wins 10% cash back. What is the effective discount?

Which of the following is correct?

Find the curved surface area (in cm2) of a right circular cone of diameter 28 cm and slant height 12 cm.

Sumit and Amit undertook a work for Rs 7200. Sumit alone can do the work in 5 days and Amit alone can do the work in 4 days. If they work together,then what will be the difference (in Rs.) in the amount they receive?

If (1 -­ cosA)/(1 + cosA) = x, then the value of x is

What is 15% of 34 ?