Question

Jane pulled weeds in the garden 7times.she was paid $5 each time she pulled weeds for less than 1 hour and $6 each time she pulled weeds for more than 1 hor.if jane received $39, how many times did she pull weeds for more than 1 hour?

Answer 1

just assume that she did it less than 1 hour x times
and more than 1 hour y times
so you can get:
`\left \{ {{5x+6y=39} \atop {x+y=7}} \right.`
and solve this equation system, you get:
`\left \{ {{x=3} \atop {y=4}} \right.`

Answer 2

Just by looking at it I can see that the answer is 4 times more than 1 hour and 3 times less than 1 hour
4*$6 = $24
3*$5 = $15
7 times = $39

If you need this for maths class though you need to know how to work it out.

To solve set up and solve a pair of simultaneous equations
Let L = less than one hour and M = more than one hour
Therefore L + M = 7 (she pulled weeds 7 times)
From this L = 7 - M

$5 * L + $6 * M = $39 (rate of pay times number of occasions = total pay)
Which mathematically can be written 5L + 6M = 39
BUT we know that L = 7 - M therefore substitutee (7 - M) for "L" in the above equation which now becomes
5(7 - M) + 6M = 39
Expand the bracket
35 - 5M + 6M = 39
Simplify
35 + M = 39

M = 4
As she pulled weeds on 7 occasions and on 4 of these she took more than one hour it follows that on 3 occasions she pulled weeds for less than one hour
L = 3