Quantitative Aptitude - Arithmetic Ability Questions

The arithmetic mean of the marks scored by students of a class is 58. 20% of them secured a mean score of 60. The mean score of another 30% of the students was 40. The mean score of the remaining students is

If the angles of a triangle are in the ratio of 1 : 4 : 7, then find the ratio of the greatest angle to the smallest angle.

Find the 4th proportional to 9, 17 and 27.

If (6 ­- 18x) -­ (x ­- 7) = 8, then the value of x is ______.

What should be the missing digit so that the number 275_476 becomes exactly divisible by 11?

The perimeter of a square is 30 cm. Find its area (in cm²).

If 3 dozen guavas cost Rs. 90, how many guavas can be bought for Rs. 240?

The ratio of salary of X, Y and Z is 15 : 3 : 8. If Z gets Rs. 3960 more than Y, then what is the salary (in Rs.) of X?