If l + m + n = 9 and l2 + m2 + n2 = 31, then the value of lm + mn + nl will be
In a city, 40% of the people are illiterate and 60% are poor. Among the rich, 10% are illiterate. The percentage of the illiterate poor population is
A trader sold a cycle at a loss of 10%. If the selling price had been increased by Rs. 200, there would have been a gain of 6%. The cost price of the cycle is
The diameters of two cylinders are in the ratio 3:2 and their volumes are equal. The ratio of their heights is
