Simply it as follows:
1 + 39 = 40
2 + 38 = 40 etc
18 + 22 = 40
19 + 21 = 40
There are 19 of these plus 40 itself . . .therefore 20 of them
20 x 40 = 800
And finally the last number not used, 20
Therefore 800 + 20 = 820
Ratio 10:6
so 10+6 = 16
112/16 =7
white balls: 10 * 7 = 70
striped balls: 6 * 7 = 42
Answer: he needs to add 70 white balls and 42 striped balls to keep the same ratio 10:6
Answer: i think is A or B
Step-by-step explanation:
Answer:
Divide both sides by 42 then reduce the fraction. The answer is 8/21=0.38
Step-by-step explanation:
