Step-by-step explanation:
(a)
ii.
21 - 5 = 16 play only chess.
iii.
23 - 5 = 18 play only cards
5 play both.
that is 16+18+5 = 39 that play at least one of these games.
i.
so, 45 - 39 = 6 don't play any of these games.
(b)
we have 16+18 = 34 pupils out of 45 that play exactly one game.
so the probabilty to pick one of them is as usual
desired cases / total cases = 34/45 =
= 0.755555555... ≈ 0.76
Answer:
63 % for cats and 37 % for dogs
Step-by-step explanation:
Answer:
72
Step-by-step explanation:
mean=average. to get average, you add up the numbers and divide by how many numbers. they add upp to 288 and since theres 4 test grades, divide by 4 to get 72.
Answer:
Step-by-step explanation:
Final concentration % = [grams of salt / mililiters of solution] * 100
grams of salt = grams of salt from solution 1 + grams of salt from solution 2
grams of salt from solution 1 = mililiters * %/100 = 80 mililiters * 0.25 g/mililiters = 20 g
grams of salt from solution 2 = mililiters *%/100 = x*0.10 g/mililiters = 0.1x
mililiters of final solution = mililiters from solution 1 + mililiters from solution 2
mililiters of final solution = 80 mililiters + x mililiters
=> Final concentration, % = [0,10x + 20 g] / [x + 80 mililiters] * 100
Ratios are basically a number v a number. Like if your in a group of 30 people and 10 of them are boys, your ratio of girls to boys would be 20:10. That's like really really basic ratio and idk how advanced in rations you are but yeah.
