The value of $${\left( {0.16} \right)^{{{\log }_{2.5}}\left( {{1 \over 3} + {1 \over {{3^2}}} + ....to\,\infty } \right)}}$$ is equal to ______.

Let A = $$\left[ {\matrix{ x & 1 \cr 1 & 0 \cr } } \right]$$, x $$ \in $$ R and A⁴ = [a_ij].
If a₁₁ = 109, then a₂₂ is equal to _______ .

A bakelite beaker has volume capacity of 500 cc at 30^oC. When it is partially filled with Vm volume (at 30^oC) of mercury, it is found that the unfilled volume of the beaker remains constant as temperature is varied. If $$\gamma $$_(beaker) = 6 × 10^{–6 o}C^–1 and $$\gamma $$_(mercury) = 1.5 × 10^{–4 o}C^–1, where $$\gamma $$ is the coefficient of volume expansion, then V_m (in cc) is close to ____.

A person of 80 kg mass is standing on the rim of a circular platform of mass 200 kg rotating about its axis at 5 revolutions per minute (rpm). The person now starts moving towards the centre of the platform. What will be the rotational speed (in rpm) of the platform when the person reaches its centre _________.