Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
Law of sines can be used to solve this problem:
(note - let x represent the missing side length.)
1. set up proportion.
sin 90°/25 = sin 55<span>°/x
2. solve.
(x) sin 90</span>° = (25) sin 55<span>°
(x) sin 90 </span>°/sin 90° = (25) sin 55° / sin 90<span>°
</span>
x = 20.4788011072
rounded to nearest tenth = 20.5
A really easy way to do this would be converting them all to decimals by dividing the top number by the bottom number.
7/5 = 1.4
15/4 = 3.75
3/2 = 1.5
11/4 = 2.75
13/3 = 4.33
Start with the whole numbers. 3/2 and 7/5 must go first since they both have a 1. 7/5 goes before 3/2 since it has a 4 in the tenths place, while 3/2 has a 5.
Next would be 11/4 since it has a 2, then 15/4 with a 3, and lastly 13/3 with a 4 as a whole number
Answer is 7/5 , 3/2 , 11/4, 15/4 , 13/3
