Quantitative Aptitude - Arithmetic Ability Questions

Dodecahedron has 20 vertices. How many edges does it have?

A sump is filled by three tankers with uniform flow. The first two tankers operating simultaneously fill the sump in the same time during which the sump is filled by the third tanker alone. The second tanker fills the sump 5 hours faster than the first tanker and 4 hours slower than the third tanker. The time required by the first tanker is:

ΔXYZ is similar to ΔPQR. If ratio of Perimeter of ΔXYZ and Perimeter of ΔPQR is 4:9 and if PQ = 27 cm, then what is the length of XY (in cm)?

The total surface area of a hemisphere is 166.32 sq cm, find its radius?

Find the value of  x3 - y3, if x - y = 4 and xy = 12.

What will be the value of r2+p2+s2-rp-ps-rs when r = 4, p = 2, s = 8?

Find the odd word/letters/number pair from the given alternatives

If Cot θ = 24/7, then Sin θ = ?