Jess has 60 ounces of an alloy that is 40% gold. How many ounces of pure gold must be added to this alloy to create a new alloy that is 75% gold?

84 ounces of pure gold

Step-by-step explanation:

Jess has 60 ounces of an alloy that is 40% gold. How many ounces of pure gold must be added to this alloy to create a new alloy that is 75% gold?

Pure gold = 100% gold

Let the number of ounces of pure gold = x

Hence, we have the equation

40% × 60 ounces + 100%× x ounces = 75%(60 + x)ounces

= 0.4 × 60 + 1x = 0.75(60 + x)

= 24 + x = 45 + 0.75x

Collect like terms

x - 0.75x = 45 - 24

0.25x = 21

x = 21/0.25

x = 84 ounces

Therefore, we need 84 ounces of pure gold

step-by-step explanation:

se a cavasery6

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true