Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd word from the given alternatives.

If 21% of an electricity bill is discounted, Rs 1817 is still to be paid. How much was the original bill amount?

20% of a man's salary is paid as rent, 60% are his living expenses and 10% are his savings. If he spends remaining  30 on the education of his children, find his salary

If a + b + c = 9 and ab + bc + ca = 18, then what is the value of a3 + b3 + c3 – 3abc?

A bag has Rs 20 in the form of 1­-rupee, 50­-paise and 10­-paise coins in the ratio of 2:3:5. Find the number of 50­-paise coins.

If u : v = v : w, then what is the value of u4 : v4?

What is the area (in cm2) of the circumcircle of a triangle whose sides are 6 cm, 8 cm and 10 cm respectively?

Mr. Raghav taught Geometry for 36 hours. If the time taken in teaching Ratio consitutes one-fourth of the time for Arithmetic, then for how much time (in hours) did he taught the topic of Ratio?