Maths problem?....No alegebra method please.Thanks.I know the nswer but don't know the workins?

Question

A sack of rice and 2 packets of green beans weigh 43kg.2 sacks of rice and a packet of green beans weigh 31kg more.Find the mass of a sack of rice.

Answer 1

From your first statement, 1 sack of rice and 2 packs of beans weigh 43kg, so 2 sacks of rice and 4 packs of beans must weigh 86kg.

The second statement says that 2 sacks of rice and one pack of beans weigh 31kg more than 43kg

Which is 74kg.

So those extra 3 packs of beans must account for the difference between 86kg and 74kg, which is 12kg.

So each pack of beans must weigh 4kg.

Going back to the first statement, a sack of rice and 8kg of beans weigh 43kg

So a sack of rice weighs 35kg

This sort of problem is so much easier to solve with a bit of algebra!

Answer 2

Use guess and check with the information they give you. It will force you to eliminate the green beans from equations but you will arrive at it naturally.

43+31=74 We do need this number to continue. Focus on the mass of the rice. We want to decide the highest mass it could have and start eliminating bad results. Half of 74 is 37. That is the most it could possibly be.

37 kg: Implies beans weighs nothing. Nope. Violates condition 1

36 kg: 2 bags weigh 72 kgs, beans must weigh only 2 kgs
36 kg bag rice + 2 kg beans + 2 kg beans <43 kgs
Violates condition 1

Speeding up:

35 kg: 2=70kg, remains 4 kg and 35kg + 4kg +4kg = 43kg
Upholds condition 1

Hope you like this O.K. It only works well if the solution will not land on a fraction.

Mass of a sack of rice = 35 kg

Answer 3

Algebra is the best way to solve this. There's no way around. You must use algebra to solve this.

Let mass of one sack of rice be x kg and the mass of one packet of beans be y kg

x + 2y = 43.....(1)
2x + y = 43 + 31 = 74.....(2)

Multiply (2) by -2
-2(2x + y) = -2*74
-4x - 2y = -148.....(3)

Add (1) and (3),
x - 4x + 2y - 2y = 43 - 148
-3x = -105
3x = 105
x = 35

One sack of rice weighs 35 kg.
There's no need to find y as only x(weight of rice) is asked.

Answer 4

1 rice + 2 green beans = 43kg----equation 1
2 rice + 1 green beans=43+31=74g-----equation 2
From equation 2, (x2), 4 rice + 2 green beans=148kg
to find rice, (4 rice + 2 green beans )-(1 rice + 2 green beans) = 148kg-43kg=105kg
3 rice= 105 kg
1 rice=105 /3
= 35kg

Answer 5

u have to use algebra method. i don think that there is any other method u solve this problem. u can use some other techniques as
1. make the two linear simultaneous equations and solve these using graphical method.
2. u can gass the values of x and y who can satisfy the equations.