Question

word problem A farmer working with his son needs 3 hours to plow a field. Working alone, the far er can law the field in 12 hours. How long would it take the son working alone to plow the field

Answer 1

F + S = 1/3 per hour

F = 1/12 per hour

S = (F + S) - F = (1/3 - 1/12) per hour = (4/12 - 1/12) per hour = 3/12 per hour = 1/4 per hour.

At 1/4 per hour, the son can plow the field in 4 hours.

Answer 2

The perimeter of a triangle is 7a - 11b. If two of its sides are 2a + b and a - 9b, what is the third side?