An ice-cream brick measures 20 cm by 10 cm by 7 cm.

Dimension of an ice cream brick $=20 \mathrm{~cm} \times 10 \mathrm{~cm} \times 7 \mathrm{~cm}$

Its volume $=$ length $\times$ breadth $\times$ height $=(20 \times 10 \times 7) \mathrm{cm}^{3}=1400 \mathrm{~cm}^{3}$

Also, it is given that the inner dimension of the deep fridge is $100 \mathrm{~cm} \times 50 \mathrm{~cm} \times 42 \mathrm{~cm}$.

Its volume $=$ length $\times$ breadth $\times$ height $=(100 \times 50 \times 42) \mathrm{cm}^{3}=210000 \mathrm{~cm}^{3}$

$\therefore$ The number of ice cream bricks that can be stored in the fridge $=\frac{\text { volume of the fridge }}{\text { volume of an ice cream brick }}=\frac{210000 \mathrm{~cm}^{3}}{1400 \mathrm{~cm}^{3}}=150$