six pencil and three rubber cost 1170naira. five pencil and two rubber cost 920naira. how much will 7 pencil and 10 rubber cost
To find out how much 7 pencils and 10 rubbers cost, we need to first determine the cost of 1 pencil and 1 rubber.
Let's assume the cost of 1 pencil is p and the cost of 1 rubber is r.
According to the given information in the problem, we can create two equations:
6p + 3r = 1170 (Equation 1)
5p + 2r = 920 (Equation 2)
We'll solve this system of equations using the elimination method.
Multiplying Equation 1 by 2 and Equation 2 by 3, we get:
12p + 6r = 2340 (Equation 3)
15p + 6r = 2760 (Equation 4)
Now, we subtract Equation 3 from Equation 4 to eliminate the r terms:
(15p + 6r) - (12p + 6r) = 2760 - 2340
15p - 12p + 6r - 6r = 420
3p = 420
p = 420 / 3
p = 140
Now, substitute the value of p into Equation 2 to find r:
5p + 2r = 920
5(140) + 2r = 920
700 + 2r = 920
2r = 920 - 700
2r = 220
r = 220 / 2
r = 110
So, the cost of 1 pencil is 140 naira and the cost of 1 rubber is 110 naira.
Now, let's find out how much 7 pencils and 10 rubbers will cost:
Cost of 7 pencils = 7 * 140 = 980 naira
Cost of 10 rubbers = 10 * 110 = 1100 naira
Therefore, the total cost of 7 pencils and 10 rubbers will be 980 + 1100 = 2080 naira.