The sum of three consecutive multiples of 5 is 285. Find the largest number.
A75
B100
C90
D120
Answer:
B. 100
Read Explanation:
Three consecutive numbers are x, x + 1 and x + 2
Three consecutive multiples of 5 are 5x, 5(x + 1) and 5(x + 2)
The sum of three consecutive multiple of 5 is 285
5x + 5x + 5 + 5x + 10 = 285
⇒ 15x = 270
⇒ x = 18
Now, largest number = 5(x + 2) = 5 × 20 = 100
