Problem $6$: $15$ pts$.$ Consider the engineering that goes into battery lifetime. Compare the energy stored in the Iphone $8$ versus the Iphone $8+.$ The Iphone $8$ is specified at $1821$mAh while the Iphone $8+$ stores $2691$mAh.

a$)$ If both phones consume approximately the same current of $130mA$ in talk mode $($they have the same guts after all$),$ what will be the talk lifetime of the two phones $(6$pts$)?$ Check your answer against the real specification.

b$)$ How much energy is stored in each of the batteries if the battery voltage is $3\mathrm{.}82$ V$.(6$pts$)$

c$)$ What is the load resistance of the entire phone $(3$ pts$)?$