Quantitative Aptitude - Arithmetic Ability Questions

In a triangle PQR, PX, QY and RZ be altitudes intersecting at O. If PO = 6 cm, PX = 8 cm and QO = 4 cm, then what is the value (in cm) of QY?

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) = ?

If x2 + (1/x2) = 1, then what is the value of x48 + x42 + x36 + x30 + x24 + x18 + x12 + x6 + 1?

A can do 1/3rd of a job in 3 days and B can do half of the job in 9 days. If they work on it together, then in how many days can they finish half of the job?

The average (arithmetic mean) amount of savings of ten students is Rs. 600. Three of the students have no savings at all and each of the others have at least Rs. 250 including Nihar, who has exactly Rs. 1300. The largest amount, in Rs., that any one student could have is

In a match, average of runs scored by 7 players is 53. If the runs scored by 6 players are 121, 40, 26, 56, 37 and 48, then how many runs did the 7th player scored?

If A, B and C can do a job working alone in 12, 18 and 36 days respectively. They all work together for 2 day, then B quits. How many days will A and C take to finish rest of the job?

The sum of a non-zero number and 9 times its reciprocal is 10. What is the number?