There are 10 boys and 20 girls in Mrs Brook's class. Mrs Brook gave all the class a test.
The mean mark for all the class is 60.
The mean mark for the girls is 56.
Work out the mean mark for the boys.

The probability that a college student belongs to a health club is 0.3. the probability that a college student lives off-campus is 0.4. the probability that a college student belongs to a health club and lives off-campus is 0.12. find the probability that a college student belongs to a health club or lives off-campus. tip: p(a or b) = p(a) + p(b) - p(a and b) 0.54 0.58 0.70 0.82

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827