In the laboratory small zircon crystals were…

In the laboratory small zircon crystals were…

In the laboratory small zircon crystals were separated from granite (rock
K). Isotopic analysis of these zircon crystals gives a
Pb207 U235 ratio of 0.45.
Using Figure 3 and the half-life of 235U (7.04 × 108
years), estimate the age of the granite in Ma to two significant figures.