+0  
 
0
1365
2
avatar

A man weighs 100 kilograms plus half its own mass. What is his total mass?

 Apr 19, 2015

Best Answer 

 #2
avatar+1904 
+5

$${\mathtt{M}} = {\mathtt{100}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{M}}}{{\mathtt{2}}}}$$

$${\mathtt{M}}{\mathtt{\,-\,}}{\frac{{\mathtt{M}}}{{\mathtt{2}}}} = {\mathtt{100}}$$

$${\frac{{\mathtt{2}}{M}}{{\mathtt{2}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{M}}}{{\mathtt{2}}}} = {\mathtt{100}}$$

$${\frac{{\mathtt{M}}}{{\mathtt{2}}}} = {\mathtt{100}}$$

$${\mathtt{M}} = {\mathtt{200}}$$

.
 Apr 19, 2015
 #1
avatar+33603 
+5

Let M be the mass. Then

 

M = 100 + M/2

 

Subtract M/2 from both sides

M/2 = 100

 

Multiply both sides by 2

M = 200 kg  (Heavy man!)

.

 Apr 19, 2015
 #2
avatar+1904 
+5
Best Answer

$${\mathtt{M}} = {\mathtt{100}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{M}}}{{\mathtt{2}}}}$$

$${\mathtt{M}}{\mathtt{\,-\,}}{\frac{{\mathtt{M}}}{{\mathtt{2}}}} = {\mathtt{100}}$$

$${\frac{{\mathtt{2}}{M}}{{\mathtt{2}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{M}}}{{\mathtt{2}}}} = {\mathtt{100}}$$

$${\frac{{\mathtt{M}}}{{\mathtt{2}}}} = {\mathtt{100}}$$

$${\mathtt{M}} = {\mathtt{200}}$$

gibsonj338 Apr 19, 2015

5 Online Users

avatar
avatar