HELP PLS I HABE BEEN STARING AT THUS QUESTION FOR SO LONG

56%

Step-by-step explanation:

Reducing the picture by 80% and then by 70% gives a reduction of 56%

70% of 80 = 0.7 × 80 = 56%

i believe the answer is c.

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870