Quantitative Aptitude - Arithmetic Ability Questions

A miner sells a diamond to a trader at a profit of 40% and the trader sells it to a customer at a profit of 25%. If the customer pays Rs 56 lakhs to buy the diamond, what had it cost the miner (in Rs lakhs)?

The average of a,b,c is 20 and that of b,c,d is 25; if d=30, then the value of a is

The average age of a class of 6 girls is x years. Four new girls having ages x – 2, x + 2, x + 4 and x + 6 joins the class. What is the new average age (in years) of the class?

If 2 T-shirts are offered free on purchase of 5 T-shirts, what is the effective discount (in %) on each T-shirt?

Rehman walks at 8 km/hr and Roma cycles at 13 km/hr towards each other. What was the distance between them when they started if they meet after 36 minutes?

What is the value of 10.2+10.02+10.002+... upto 9 terms

What should come in place of question mark (?) in the following question? (You do not have to calculate the exact value.)

(√80.997 - √25.001) × (√120.98 + √16.02) = ?

A shopkeeper by selling 5 items, earns a profit equal to the selling price of 1 item. What is his profit percentage?