Class 10R sat a test The mean mark for the class was 70% there are 30 students in class 10R, 20 of whom are boys the mean mark for the boys in the test was 62% work out the mean marks for the girls

86

Step-by-step explanation:

Given that there are 30 students in class 10R and the mean marks for the entire class was 70%. Therefore, total mark of class = 70 x 30 = 2100

Given that there are 20 boys in the class and the mean marks for the boys was 62 %. Therefore, total mark of boys = 62 x 20 = 1240

To calculate the mean mark for the girls we need to find the total number of girl and total mark of girls. total number of girl = 30 - 20 (boys) = 10 total mark of girls = total mark of class -  total mark of boys = 2100 - 1240 = 860 mean mark for girls = 860 / 10 = 86

what are ur choices?

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.