
David W. answered 03/27/17
Tutor
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Experienced Prof
After careful reading, we determine that there are just two variables for which we must solve:
x = the number of apples at first
y = the number of mangoes at first
Note: the basket contains only apples and mangoes, so (x+y) = total number of fruits at first
Translate:
"85% of the fruits in a basket were apples" means x = (85/100)(x+y) [eq1]
[note: 85% may be written as (85/100) or 0.85 as needed by the problem]
"the rest were mangoes" means y = (15/100)(x+y) [eq2]
"141 more apples and mangoes were added " means
new total number in the basket is now (x+y+141)
"percentage of apples increased by 20%" and
"numbers of mangoes tripled" means
new number of apples + new number of mangoes = new total
(120/100)x + 3y = (x+y+141) [eq3]
(x+y) = (100/85)x [from eq1]
y = (100/85)x - x
y = (100/85)x - (85/85)x
y = ((100-85)/85)x
y = (15/85)x
y = (3/17)x [eq4]
(120/100)x + 3(3/17)x = x + (3/17)x + 141 [substitute into eq3]
2040x + 900x = 1700x + 300x + 239700 [multiply by 1700 to get rid of fractions]
940x = 239700
x = 255
There were 255 apples in the basket at first.
Check:
There were (3/17)255 = 45 mangoes at first. [use eq4]
At the end, there were (120/100)(255) = 306 apples.
At the end there were (3*45) = 135 mangoes.
That's (306-255) + (135-45) = 51 + 90 = 141 more apples and mangoes; CHECK!