Compound X contains elements A and B at an approximate ratio, by weight, of 2:10. Approximately how many grams of element B are there in 342 grams of compound X?
Choose the correct choice from the following choices.
A) 54 B) 162 C) 250 D) 270 E) 280
total number of fractions =2+10= 
<gadget id="calculator">2+10</gadget>
<output>12</output>
12   element B constitutes=10 out of 12 parts of X   So in 342 gms of X have 342*10/12=280 gms of B   and  342-280= 
<gadget id="calculator"> 342-280</gadget>
<output>62</output>
62 gms of A.   cross check:- A/B= 62/280 =2/10 (as given)   Ans 280
<result>E</result>
Compound X contains elements A and B at an approximate ratio, by weight, of 2:10. Approximately how many grams of element B are there in 342 grams of compound X?