Resistors in Series and Parallel

The total resistance is 25 kΩ, what is the value of R in kΩ?

Write the values only in the blanks.

A 6 Ω resistor and an unknown value resistor are connected in series to a 12 V supply. When the p.d. across the 6 Ω resistor is measured as 9 V, what is the value of the unknown resistor? Write the value only which is expressed in Ω.

Five 3.5 Ω, ten 100 Ω and three 10 Ω resistors are all connected in parallel, what is the value of equivalent resistance in Ω rounded up 2 significant figures? Write the values only in the blanks.

Three resistors of 1 Ω, 2 Ω and 5 Ω are connected in parallel across a 20 V supply. Find the total current in the circuit in A. Write the value only.

Calculate the total resistance between terminals A and B. Express your answers in 2 significant figures and write the value only expressed in ohms.

Calculate the total power of the circuit. Write the values only that is expressed in kW.