The cost of a pen and a book are in the ratio of 5:3 respectively. If a pen costs sh. 2000, What is the cost of a book? 2. The cost of book and rulers in the ratio of 5:1. What is the cost of a book if a ruler costs costs sh. 250

Gharama ya kalamu : Gharama ya kitabu = $5 : 3$.
Tunajua gharama ya kalamu ni sh 2000.

Hebu $C_k$ iwe gharama ya kalamu na $C_b$ iwe gharama ya kitabu.

Badilisha gharama ya kalamu:

Gawanya pande zote mbili kwa 5:

Gharama ya kitabu ni sh 1200.

Gharama ya kitabu ni $\boxed{\text{sh 1200}}$.

2. Tatizo la Pili:

Gharama ya kitabu : Gharama ya rula = $8 : 1$.
Tunajua gharama ya rula ni sh 250.

Hebu $C_b$ iwe gharama ya kitabu na $C_r$ iwe gharama ya rula.

Badilisha gharama ya rula:

Gharama ya kitabu ni sh 2000.

Gharama ya kitabu ni $\boxed{\text{sh 2000}}$.