huda wrote:
sandy wrote:
Dwayne planted 70 acres with two types of beans: navy and pinto. Each acre of navy beans yielded 27 bushels and each acre of pinto beans yielded 36 bushels. If Dwayne grew twice as many bushels of pinto beans as navy beans, how many acres of pinto beans did he plant?
(A) 28
(B) 30
(C) 35
(D) 40
(E) 42
any easy way to solve it?I don't think there's a shortcut, but I don't like the wordiness of the official explanation. There's need to confuse yourself with big equations. You just need to build 2 equations like how you are taught in school.
1. Building the first equation is easy.
AcresN + AcresP = 702. Building the second equation is a bit tricky because it's actually made of 2 mini parts.
>>
BushelsN = AcresN x 27>> BushelsP = AcresP x 36 -->
2(BushelsN) = AcresP x 36Solve for AcresN and AcresP and plug them back into equation 1.
>> AcresN = BushelsN/27
>> AcresP = 2(BushelsN)/36
>> [BushelsN/27] + [2(BushelsN)/36] = 70
The rest is easy:
BushelsN is 756
BushelsP is 1512
AcresP = 1512/36 = 42 acres