BART A & B car ratio

[jackintosh11]

Wikipedia says that BART has 59 A cars and 389 B cars, all built from 1968-1971. That means for every A car, there are 6.5 B cars. How is this possible? Were some of the A cars converted to B cars after the purchase of C cars?

[lensovet]

some cars have presumably been lost to accidents or shelved for parts…

[Silverliner II]

Wikipedia says that BART has 59 A cars and 389 B cars, all built from 1968-1971. That means for every A car, there are 6.5 B cars. How is this possible? Were some of the A cars converted to B cars after the purchase of C cars?

When the A and B cars were overhauled, and after the second order of C cars arrived, many of the A cars were indeed rebuilt into B cars.