n investment of ​$93 comma 000 was made by a business club. The investment was split into three parts and lasted for one year. The first part of the investment earned​ 8% interest, the second​ 6%, and the third​ 9%. Total interest from the investments was $ 7110. The interest from the first investment was 3 times the interest from the second. Find the amounts of the three parts of the investment.

Question

What is the amount of the first part of the​ investment? ​$
nothing

Answer 1

Translation into English:
An investment of ​$93,000 was made by a business club
-first investment paid 8%, let it be x
-2nd investment paid 6% , let it be y
- 3rd investment paid 9% , let it be z
but x = 3y
so x + y + z = 93000
3y + y + z = 93000
z = 93000 - 4y

.08x + .06y + .09z = 7111
times 100
8x + 6y + 9z = 711100
24y + 6y + 9(93000 - 4y) = 711100

solve for y, then you can find x and z

Answer 2

amounts a , b and c
a + b + c = 93000
.08 a + .06 b + .09 c = 7110
.08 a = 3 * .06 b ....... so b = .444 a
now
a + .444 a + c = 93000
.08 a + .06*(.444)a +.09 c = 7110
divide the second one by .09
1.444 a + c = 93000
1.185 a +c = 79000
----------------------------subtract
.259 a = 14000
a = 54,054