Quantitative Aptitude - Arithmetic Ability Questions

If ax= by= cz and b2= ac, then what is 1x+1z equal to ?

X can complete 5/7 part of a work in 10 days and Y can complete 3/4 part of the same work in 9 days. In how many days will both complete 13/21 part  of the total work?

A, B and C can do a job working alone in 12, 16 and 24 days respectively. In how many days they can do the job if they worked together?

P and Q can do a project in 150 and 100 days respectively. In how many days can they complete 60% of the project if they work together?

Ravi invested Rs.P in a scheme A offering simple interest at 10% p.a. for two years. He invested the whole amount he received from scheme A, in another scheme (B) offering simple interest at 12% p.a. for five years. If the difference between the interests earned from schemes A and B was Rs. 13,00/, what is the value of P ?

3/5 as a decimal fraction?

What approximate value should come in place of the question mark (?) in the following equation (Note: You are not expected to calculate the exact value)?

[(7.99)2–(13.001)2+(4.01)3]2=?

A uniformly moving train of length 480 m takes 3 minutes to completely cross a platform. If the same train, with the same speed crosses a pole completely in 30 sec, then the length of the platform is -