Quantitative Aptitude - Arithmetic Ability Questions

If a+b+c = 6 and ab+bc+ca = 1, then the value of bc(b+c) + ca(c+a) +ab(a+b) +3abc is

To travel 720 km, a Express train takes 6 hours more than Duronto. If however, the speed of the Express train is doubled, it takes 2 hours less than Duronto. The speed of Duronto (in km/hr) is?

What is the value of 729+72.9+7.29

The ratio of the members of blue to red balls in abag is constant. When there were 44 red balls, the number of blue balls was 36. If the number of blue balls is 54, how many red balls will be in the bag?

Calculate the future value of $3,000 invested at 7% for 5 years

A does 75% of a work in 25 days. He then calls in B and they together finish the remaining work in 5 days. How long B alone would take to do the whole work?

From well shuffled standard pack of 52 playing cards,one card is drawn. What is the probability that it is either a red card or black card?

Three  cars A, B and C  started  from  a  point at 5  pm, 6  pm  and 7  pm respectively and travelled at uniform speeds of 60 km/hr, 80 km/hr and x km/hr respectively in the same direction. If all the three met at another point at the same instant during their journey, then what is the value of x?