Activity 1: Whlo bolwezi, phyzo ingan, lesi phyzo ingam ba nga sinye yesi phyzo esu pham a kethe ezizo thang

$$R20 + R10 + R15 = R45$$

The sum is $\boxed{\text{R45}}$.

$$2500 - 1600 = 900$$

The difference is $\boxed{\text{R900}}$.

$$15 \times 60 = 900$$

The product is $\boxed{\text{R900}}$.

$$\frac{60}{6} = 10$$

The result is $\boxed{10}$.

$$60 \div 10 = 6$$

The result is $\boxed{6}$ days.