Here is the questionnaire administered for the the grade 7 of Alabel National Science High School for Fourh Grading period.
Here are some mathematics questions that were administered during some mathematics competitions.
Work Problem No. 2
Greg can milk all of the carabaos in 120 minutes and Harold can do it in 60 minutes. If Greg milks for 20 minutes before Harold joins him, how long would it take them to finish?
Solution:
Let x be the length of time Greg and Harold can finish milking the carabaos.
Rate (job per minute) Time Work
Greg 1/120 x + 20 ( x + 20 ) / 120
Harold 1/60 x x/60
Equation: ( x + 20 ) / 120 + x/60 = 1
To solve, multiply both sides of the equation by the LCD, i.e.
120 ( ( x + 20 ) / 120 + x/60 ) = ( 1 ) 120
x + 20 + 2x = 120
3x + 20 = 120
3x = 120 - 20
3x = 100
x = 100/3
x = 33 1/3 minutes or 13 minutes and 20 seconds.
Therefore, Greg and Harold can milk all the carabaos in 13 minutes and 20 seconds.
Problem is taken from e-math kto12 edition Grade 7
Solution:
Let x be the length of time Greg and Harold can finish milking the carabaos.
Rate (job per minute) Time Work
Greg 1/120 x + 20 ( x + 20 ) / 120
Harold 1/60 x x/60
Equation: ( x + 20 ) / 120 + x/60 = 1
To solve, multiply both sides of the equation by the LCD, i.e.
120 ( ( x + 20 ) / 120 + x/60 ) = ( 1 ) 120
x + 20 + 2x = 120
3x + 20 = 120
3x = 120 - 20
3x = 100
x = 100/3
x = 33 1/3 minutes or 13 minutes and 20 seconds.
Therefore, Greg and Harold can milk all the carabaos in 13 minutes and 20 seconds.
Problem is taken from e-math kto12 edition Grade 7
Work Problem No. 1
Dan can do the job in 30 hours, Ellen can do it in 40 hours, and Francis can do it in 60 hours. how long would it take them if they work together?
Solution:
Let x be the number of hour Dan, Ellen, and Francis take if they work together.
Name Rate (job per hour) Time Work
Dan 1/30 x x/30
Ellen 1/40 x x/40
Francis 1/60 x x/60
Equation: x/30 + x/40 + x/60 = 1
To solve, multiply both sides of the equation by the LCD, i.e.
120 ( x/30 + x/40 + x/60 ) = ( 1 ) 120
4x + 3x + 2x = 120
9x = 120
x = 120/9
x = 13 1/3 hours or 13 hours and 20 minutes.
Therefore, Dan, Ellen, and Francis can finish the job in 13 hours and 20 minutes if they work together.
Problem is taken from e-math kto12 grade 7
Solution:
Let x be the number of hour Dan, Ellen, and Francis take if they work together.
Name Rate (job per hour) Time Work
Dan 1/30 x x/30
Ellen 1/40 x x/40
Francis 1/60 x x/60
Equation: x/30 + x/40 + x/60 = 1
To solve, multiply both sides of the equation by the LCD, i.e.
120 ( x/30 + x/40 + x/60 ) = ( 1 ) 120
4x + 3x + 2x = 120
9x = 120
x = 120/9
x = 13 1/3 hours or 13 hours and 20 minutes.
Therefore, Dan, Ellen, and Francis can finish the job in 13 hours and 20 minutes if they work together.
Problem is taken from e-math kto12 grade 7
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