Answer:
see below
Step-by-step explanation:
butterfly = x minutes
breast = y minutes
total is 50 minutes
breast stroke = butterfly +20
Part A
x+y = 50
y = x+20
Part B
Substitute the second equation into the first
x+ (x+20) = 50
2x+20 = 50
2x+20-20 = 50-20
2x = 30
2x/2 = 30/2
x = 15
y = x+20
y = 20+15
y = 35 minutes
35 minutes on the breast stroke
Part C
45 minutes on the butterfly is not reasonable
We only have a total of 50 minutes
50-45 = 5
But he spend more time on the breast stroke ( 20 minutes more), but if he spend 45 minutes on the butterfly, he would have to spend less on the breast stroke.
Answer:437.5
Step-by-step explanation:3.5 times 250=875 divided by2 =437.5
The right answer is Option C : 5
Step-by-step explanation:
Let,
The numerator of fraction = x
The denominator of a fraction is 10 more than its numerator.

When 1/3 is added to this fraction,

the resulting fraction’s denominator is three times the denominator of the original fraction its numerator is 15 less than its denominator

Therefore, it becomes

Taking LCM on left side

Multiplying both sides by 3(x+10)

The numerator of original fraction is 5.
The right answer is Option C : 5
Keywords: fraction, addition
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