Respuesta :

Answer:

A

Step-by-step explanation:

We are starting with 51

50x10=50

1x1=1

since there were 0.21 seconds, we first have to find the tenths place.

0.1x2=0.2

now that we found the tenths place, we need to find the hundredths place

0.01x1=1

FINAL ANSWER

(5 x 10) + (1 x 1) + (2 x 0.1) + (1 x 0.01)