Last year the depth of the river was 4.2 feet deep. This year it dropped 19%.

Find the depth of the river this year to cross it.

3.402

Step-by-step explanation:

If it dropped 19% that means it is only 0.81 of the depth last year. Multiplying 0.81 by 4.2 gives 3.402.

0.0076, if you meant 4.125 divided by 0.03125 it would be 132

step-by-step explanation:

first you have to move the decimal in 0.03125 over until its behind the 5 which is 5 places over. now the number is 3125

then you have to move the decimal in 4.125, 5 places over. now the number is 4,112,500.

now you divide like you would normally would and get 0.0076