Quantitative Aptitude - Arithmetic Ability Questions

If a2+b2+c2=83and a+b+c=15 then the value of ab+bc+ca is

A person clapped his hands near a cliff and heard echo after 6 s. The distance of the cliff from the personis: [take v = 346 m/s]

When 0.090909.....is converted into a fraction, then the result is

A can do a work in 36 days and B in 12 days. If they work on it together for 3 days, then what fraction of work is left?

What would be the smaller of the two angles formed by the hour hand and the minute hand at 4:52 p.m?

If x + y = 10 and x2 + y2 = 68, then find xy

P(3,1) and R(-7,5) are vertices of a rhombus PQRS. What is the equation of diagonal QS?

If θ is positive acute angle and 7cos2Ɵ + 3sin2Ɵ = 4, then the value of θ is