If 4/10 of the population have blood type O+, that means 40% of the population have that blood type. To change a fraction to percent, the easiest way is to make the denominator 100. To do this, multiply the whole fraction by 1 (1/1, 2/2, etc). In this case, multiply by 10/10. 4/10 * 10/10 is equal to 40/100. Then, if you have a denominator of 100, the numerator is the percent. Therefore, 40/100 is 40%.
Answer:
Country A = 84
Country B = 28
Country C = 18
Step-by-step explanation:
Country A, Country B, and Country C won a total of 130 medals;
A + B + C = 130 ......1
Country B won 10 more medals than Country C;
B = C + 10 .......2
Country A won 38 more medals than the total amount won by the other two;
A = B + C + 38 ........3
Substituting equation 3 to 1;
(B+C+38) + B+C = 130
2B + 2C + 38 = 130 .......4
Substituting equation 2 into 4;
2(C+10) + 2C + 38 = 130
4C + 58 = 130
4C = 130-58 = 72
C = 72/4 = 18
B = C + 10 = 18 + 10 = 28
A = B + C + 38 = 18 + 28 + 38 = 84
Country A = 84
Country B = 28
Country C = 18
Answer:

Step-by-step explanation:
Given

Required
Probability of selecting 2 toys of different types
From the question, we understand that all toys are different i.e. 1 of each type.
And the selection is without replacement;
So, after the first toy is selected; there are n - 1 toys left.
So, the probability is:

Substitute 



