Deers and roes live in the forest. Deers make up 30% of the forest life. There are 144 deers less than roes. How many roes live in the forest? Answer: 252 roes. How do I solve this problem?

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Answer 1 · 2016-03-10T09:00:49

Convert the problem into equations that can be solved for the number of roe.

If #x# is the number of roes, then the number of deer is #x-144#

If #T# is the total, then deer are #0.3*T#

#x+(x-144)=T#
#2x = T +144#

#x-144 = 0.3*T#
#x= (3T)/10 +144#

Substituting, #2((3T)/10 +144) = T+144#
#(3T)/5 -T = 144 - 288#
#2T = 144*5 = 720#

#T = 360#

#x=108 + 144 = 252#