There are 10 girls and 20 boys in a class. The class has a test. The mean mark for all the class is 70.
The mean mark for all the boys is 62 Work out the mean mark for the girls.

74 marks

Step-by-step explanation:

As there are 10 girls and 20 boys, there are a total of 30 students in the class.

If the mean mark for all 30 students is 70, this means that there was a combined total score of 70 x 30 = 2100.

If the mean mark for all 10 boys was 62, this means that there was a combined total score for boys of 62 x 10 = 620.

2100 - 620 = 1480 marks in total for the girls

As there are 20 girls in the class, 1480/20 = 74

This means that the mean for the girls in the class is 74 marks.

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

a.)the line for function b is steeper