In the following $APs,$ find the missing term in the box: $2, \square, 26$

Write the first four terms of the $AP,$ when the first term $a$ and the common difference $d$ are given as follows: $a = -1, d = \frac{1}{2}$

Find the $31^{st}$ term of an $AP$ whose $11^{th}$ term is $38$ and the $16^{th}$ term is $73.$

How many multiples of $4$ lie between $10$ and $250$?

Which term of the $AP: 3, 15, 27, 39, \ldots$ will be $132$ more than its $54^{th}$ term?

$A$ spiral is made up of successive semicircles,with centres alternately at $A$ and $B$,starting with centre at $A$,of radii $0.5 \, cm, 1.0 \, cm, 1.5 \, cm, 2.0 \, cm, \ldots$ as shown in the figure. What is the total length of such a spiral made up of thirteen consecutive semicircles? (Take $\pi = \frac{22}{7}$)