Quantitative Aptitude - Arithmetic Ability Questions

Which of the following is correct?

The sum of three consecutive natural numbers each divisible by 5, is 225. The largest among them is

A, B and C are employed to complete a work in Rs. 784. If A and B together complete 23/28 of the work. Calculate the wages (in Rs.) paid to C?

A, B and C can do a job working alone in 6, 9 and 18 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to complete the remainder of the job?

ABCD is a quadrilateral in which BD and AC are diagonals then

If 4r = h + r2+h2 then r: h = ? (r not equal to 0)

A businessman imported Laptops, worth Rs 210000, Mobile phones worth Rs 100000 and Television sets worth Rs 150000. He had to pay 10% duty on laptops, 8% on Phones and 5% on Television sets as a special case. How much total duty (in Rupees) he had to pay on all items as per above details?

If 5/2 - (6/5)(x - 15/2) = -x/5, then what is the value of x?