Quantitative Aptitude - Arithmetic Ability Questions

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

If 3a+4b3c+4d = 3a-4b3c-4d, then 

If on an item there is 12% discount on the marked price of Rs 10,000 but the item is sold at Rs 8,360 only then what additional discount (in %) did the customer get?

From an external point two tangents to a circle are drawn. The chord passing through the points of contact subtends an angle72° at the centre. The angle between the tangents is?

What is the sum of all natural numbers between 100 and 400 which are divisible by 13?

The length of diagonal BD of a parallelogram ABCD is 36 cm. P and Q are the centroids of triangle ABC and triangle ADC respectively. What is the length (in cm) of PQ?

10 persons can do a job in X days. If 20 persons with twice the efficiency can do the same job in 5 days, then find the value of X?

In a company 2/3 of the workers are girls, 1/2 of the girls are married and 1/3 of the married girls live in hostel. If 3/4 of the boys are married and 2/3 of married boys live in hostel. Calculate the part of workers who don’t live in hostel.