Answer:
Number of 50sen coins = 13
Step-by-step explanation:
Let the number of 50sen coins be = x
Let the number of 20sen coins be = y
Total coins = 20
x + y = 20 ----------------------(i)
Value of 50sen coins = 0.50*x = 0.50x
Value of 20sen coins = 0.20 *y = 0.20y
Total value = RM 6.10
0.5x + 0.2y = 6.10 -------------------(ii)
Multiply (i) by (-0.5) and then add the equations. So, x will be eliminated and we can find the value of y
(i) * (-0.5) -0.5x - 0.5y = -10
(ii) 0.5x + 0.2y = 6.10 { add and now x will be eliminated}
- 0.3y = -3.90
Divide both sides by (-0.3)
y = -3.90/-0.3
y = 13
Plug in the value of y in equation (i)
x + 13 = 20
Subtract 13 from both sides
x = 20 -13
x = 7
Number of 50sen coins = 13
