Quantitative Aptitude - Arithmetic Ability Questions

If N = 0.369369369369... and M = 0.531531531531..., then what is the value of (1/N) + (1/M)?

What is the rate of interest (in %) if simple interest earned on a certain sum for the 3 years is Rs 6,000 and compound interest earned for 2 years is Rs 4,160?

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

What least value must be assigned to '*' so that the numbers 451 *  603 is exactly divisible by 9?

Tan 45° + Cosec 60° =

PQRS is a square whose side is 20 cm. By joining opposite vertices of PQRS are get four triangles. What is the sum of the perimeters of the four triangles?

Type 1 workers are 2.5 times as efficient as type 2 workers. Twelve Type 1 workers can complete a task in 10 days. How many days would it have taken 4 Type 1 and 15 Type 2 workers to do the same work?

The ratio of ages of father and son is 7:2. Five years ago the product of their ages was 150. What is the age of the father?