84 blue marbles.
Steps:
1) Use the 3:7 ratio
2) Since there are 36 red marbles, you should know to multiply the ratio by 12.
3) Multiply 7 by 12 (7x12=84)
Let's say the width is (x) and the width is (x+12). The formula for a perimeter of a rectangle equals 2w + 2l, which would then for this problem be 100=2(x) + 2(x+12) which would distribute as 2x + 2x + 12 which equals 4x+12. When you subtract twelve from 100 you get 88=4x. Divide 88 by 4 and you get x=22. This then would mean the width is 22 and the length is 34. The formula for an area of a rectangle is w*l. Plug in the numbers that you figure out from the area formula and you get 22x34=748
9514 1404 393
Answer:
Step-by-step explanation:
6 of the 10 bars are shaded, so the shaded area is 6/10 of the whole.
"Six tenths" as a decimal is 0.6, that is, a number with 6 in the tenths place.
To convert the number to a percent, multiply either the fraction or the decimal by 100%.
0.6 × 100% = 60%
