Question

a 15 foot lamp casts a 9-ft shadow if the streetlamp is near a 70 ft tall building find the length of the shadow cast by the building​

Answer 1

42 feet

Explanation:

This is a ratio question. The ratio of the height of the lamp to its shadow is the same as the ratio of the height of the building to its shadow.

So, 15/9 = 70/x, where x is the building's shadow.

Cross mutiply and solve for x.

15x = 630

x=42