Seorang penjual beras mencampur 3 jenis beras. campuran pertama terdiri atas 1 kg jenis a , 2 kg jenis b , dan 4 kg jenis c dijual dengan harga Rp.19.500 . campuran beras kedua terdiri dari 2 kg jenis a dan 3 kg jenis b dijual harga Rp.19.000 . campuran beras ketiga terdiri atas 1 kg jenis b dan 1 kg jenis c dijual dengan harg Rp.6.250 . harga beras jenis manakah yang paling mahal
Accepted Solution
A:
Translation to English:
A rice supplier mixes three different types of rice into three different blends; Type A, Type B, and Type C.
He blends 1 kg of type A, 2 kg of type B, and 4 kg of type C and sells the blend for IDR 19500 He also blends 2 kg of type A and 3 kg of type B and sells the blend for IDR 19000 The third blend consists of 1 kg of type B and 1 kg of type C and this blend is sold for IDR 6250
Which type of rice is the most expensive?
Solution:
Start with the third blend: 1 kg of type B + 1 kg of type C = 6250 B + C = 6250 B = 6250 - C
Then move on to the second blend: 2 kg of type A + 3 kg of type B = 19000 2A + 3B = 19000 2A + 3(6250 - C) = 19000 2A + 18750 - 3C = 19000 2A - 3C = 19000 - 18750 2A - 3C = 250 2A = 250 + 3C A = [250 + 3C] / 2
Then move on to the first blend: 1 kg of type A + 2 kg of type B + 4 kg of type C = 19500 A + 2B + 4C = 19500 [tex] \frac{250+3C}{2}+2(6250-C)+4C=19500 [/tex] ⇒ Multiply each term by 2 [tex](250+3C)+4(6250-C)+8C=39000[/tex] [tex]250+3C+25000-4C+8C=39000[/tex] [tex]25250+7C=39000[/tex] [tex]7C=39000-25250[/tex] [tex]7C = 13750[/tex] [tex]C=1964.3[/tex]
B + C = 6250 B + 1964.3 = 6250 B = 6250 - 1964.3 B = 4285.7