Tammy climbed a mountain in two days. She spent a total of

Time on day 1 = x
Time on day 2 = x - 2
Total time = Day 1 + Day 2
14 = x + x -2
14 = 2x - 2
16 = 2x
x = 8
$$Total\ speed\ =\ \frac{Total\ dis\tan ce}{Total\ time}$$
$$Day\ 1\ =\ speed\ \cdot\ 8=Dis\tan ce$$
$$Day\ 2=\ \left(Speed+0.5\right)\cdot6=52-d$$
$$52=s\cdot8+\left(s+0.5\right)\left(8-2\right)$$
$$52=8s+8s-2s+4-1$$
$$52=14s+3$$
$$\frac{49}{14}=\frac{14s}{14}$$
$$s=3.5$$
But her speed was 0.5 km/hr faster on day 2
Day 2 speed $$3.5+0.5=4.0\ \frac{km}{hr}$$
$$Answer\ is\ Option\ C$$