How many tripeptides can be prepared by linking the amino acids glycine,alanine and phenylalanine?

$A$ solution containing $10 \ g$ per $dm^3$ of urea (molecular mass $= 60 \ g \ mol^{-1}$) is isotonic with a $5 \%$ solution of a non-volatile solute. The molecular mass of the non-volatile solute is ........ $g \ mol^{-1}$.

If $f(x) = \sin x + \cos x$,then $f\left(\frac{\pi}{4}\right) f^{(iv)}\left(\frac{\pi}{4}\right)$ is equal to

If the lines $x^2+2xy-35y^2-4x+44y-12=0$ and $5x+\lambda y-8=0$ are concurrent,then $\lambda$ equals

If $\tan ^{-1} x = y$,then . . . . . . .

$A$ pendulum suspended from the ceiling of a train oscillates with a time period $2\,s$,when the train is accelerating at $10\,m/s^2$. What will be its time period when the train retards at $10\,m/s^2$?