Sol cycled to raise funds for a charitable organization. On the first day, he cycled 48km for the first 10 days, he cycled 2km less on each subsequent day. Thereafter, he cycled 2km less on each subsequent day.

Kutokana na maelezo, Soi aliendesha baiskeli 40km siku ya kwanza. Kisha, aliendesha 2km pungufu kila siku inayofuata. Hii inaunda mfululizo wa hesabu (arithmetic progression) ambapo:
Neno la kwanza ($a$) = 40 km
Tofauti ya kawaida ($d$) = -2 km (kwa sababu umbali unapungua)
Fomula ya neno la $n$ katika mfululizo wa hesabu ni $a_n = a + (n-1)d$.

Tumia $n=10$ katika fomula:

Umbali uliosafiriwa siku ya 10 ni $\boxed{22 \text{ km}}$.

Kama ilivyo hapo juu, $a = 40$ km na $d = -2$ km.

Tumia $n=16$ katika fomula:

Umbali uliosafiriwa siku ya 16 ni $\boxed{10 \text{ km}}$.

Soi ataendelea kuendesha baiskeli hadi umbali uwe 0 au chini. Tutapata $n$ wakati $a_n = 0$.

Kwa hivyo, Soi aliendesha baiskeli kwa siku 21.

Jumla ya mfululizo wa hesabu ni $S_n = \frac{n}{2}(a + a_n)$.
Hapa, $n=21$, $a=40$, na $a_{21}=0$ (umbali siku ya 21).

Kiwango cha kukusanya pesa ni Ksh 200 kwa kila Km.

Jumla ya pesa zilizokusanywa ni $\boxed{\text{Ksh 84000}}$.