Question:
One number is 7 times a first number. A third number is 100 more than the first number. If the sum of the three numbers is 505, Find the numbers.
Answer:
The numbers are 45, 315 and 145
Step-by-step explanation:
Represent the three numbers with A, B and C
Required
Find A, B and C
From the first statement;
[tex]B = 7 * A[/tex]
[tex]B = 7A[/tex] --- (i)
From the second;
[tex]C = 100 + A[/tex] ---- (ii)
From the third;
[tex]A + B + C = 505[/tex] ---- (iii)
Substitute 7A for B and 100 + A for C in (iii)
[tex]A + 7A + 100 + A = 505[/tex]
Collect like terms
[tex]A + 7A + A = 505 - 100[/tex]
[tex]9A = 405[/tex]
Divide both sides by 9
[tex]A = 45[/tex]
Substitute 45 for A in (i)
[tex]B = 7A[/tex]
[tex]B = 7 * 45[/tex]
[tex]B = 315[/tex]
Substitute 45 for A in (ii)
[tex]C = 100 + A[/tex]
[tex]C = 100 + 45[/tex]
[tex]C = 145[/tex]
Hence, the numbers are 45, 315 and 145