One mouse weighs 20% more than another mouse...

Question

Simple pictures may help you solve some of these problems.

 

One mouse weighs 20% more than another mouse. Together, the two mice weigh 66 grams. How much does each mouse weigh? Explain your reasoning. 

Answer 1

So let us name each mouse. Mouse 1 will weigh a and mouse 2 will weigh b

 

So, our equation is 

 

a + b = 66_grams

 

 

now, mouse b weighs a + 0.2a  so we can replace b with a + 0.2a. plug that into the original equation.

 

a + (a + .2a) = 66_grams

 

we can combine these terms to get

 

2.2a = 66_grams

 

solve for a you get mouse 1 weight

 

a = 66/2.2 = 30 grams

 

mouse 1 weighs 30 grams

 

now, we can replace the equation we used for b to get mouse two's weight

 

b = a + 0.2a = 30 + 0.2(30) = 36 grams

 

mouse 2 weighs 36 grams

 

to verify plug these back into the first equation we made

 

a + b = 66

30 + 36 = 66 grams