SAT (Stage-2) M...

A test has 50 questions. A student scores 1 mark for a correct answer, -1/3 for a wrong answer and -1/6 for not attempting a question. If the net score of a student is 32, the number of questions answered wrongly by that student cannot be less than

If the zeros of the quadratic polynomial ax² + bx + c (c ≠ 0) are equal, then

Two circles touch each other externally such that the shortest distance between their centres is 12 cm and the sum of their areas is 74π cm². What is the difference between their radii?

A metallic spherical shell of internal and external diameters respectively 4 cm and 8 cm is melted and recast into a cone of base diameter 8 cm. The height of the cone is

If two solid hemispheres of the same radius 'r' are joined together along their bases, then the curved surface area of this new solid would be

A grouped frequency table with class intervals of equal size, using 250 - 270 (270 not included in this interval) as one of the class intervals, is constructed for the following data:

268, 220, 368, 258, 242, 310, 272, 342, 310, 290, 300, 320, 319, 304, 402, 318, 406, 292, 354, 278, 210, 240, 330, 316, 406, 215, 258, 236

The frequency of the class 310 - 330 is