(a)[1]
Simplify the expression $3g + 7g - 4g$.
(b)[2]
Solve the equation $4x + 5 = 27$.
(c)[1]
Given $6^p \times 6^3 = 6^{17}$, determine the value of $p$.
(d)[6]
Write down a pair of simultaneous equations and use them to find the cost of a calculator and the cost of a pen.