An electronics shop offers a small ic chip for $1.50 per unit and $4.00 for large ic chip. on a certain day, 2200 chips were sold and $5050 is collected. how many small ic chips and how many large ic chips were sold?

Let s and l represent the numbers of small and large ICs sold that day. The problem statement gives rise to two equations.
.. s + l = 2200
.. 1.50s +4.00l = 5050

Solving these by your favorite method gives
.. s = 1500
.. l = 700

1500 small ICs and 700 large ICs were sold.