Quantitative Aptitude - Arithmetic Ability Questions

What is the largest 4 digit number which is exactly divisible by 81?

The sum of the digits of a 2-digit number is 8. If we add 36 to the number, the new number obtained is a number formed by interchange of the digits. What is the number?

$$\begin{gathered} ∆ABC is similar to ∆PQR. If ratio of perimeters of ∆ABC and ∆PQR is 1:2 and \\ if PQ = 10 cm then what is the length of AB (in cm)? \end{gathered}$$

What is the value 32cos 39sin 51-sin239 + sin251

Determine the value of ‘r’ for which the equation 13x + 5 = rx + 18 has no solution.

If cotθ = 4, then the value of 5sinθ+3cosθ5sinθ-3cosθ is

In ΔPQR, S and T are points on side PQ and PR respectively. ST is parallel to QR. If S divides PQ in the ratio 4:1 and length of QR is 15 cm,what is the length of ST?

Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs 1200 for 2 years at 10% per annum. The sum placed on simple interest is