Brandon mows his lawn once every 5 days. Thomas mows his lawn every 3 days. If they are all mowing there lawn today, how many days will they be mowing there lawn together again?

A. 3

B. 5

C. 8

D. 15

Answer: D. 15

Step-by-step explanation:

Given : Brandon mows his lawn once every 5 days.

Thomas mows his lawn every 3 days.

If they are all mowing there lawn today, then the number of days after which they will be mowing there lawn together again = LCM (5, 3)

[LCM = Least common multiple]

Since 5 and 3 are co primes (having no common factor other than 1),

so LCM (5,3) = 5 x 3 = 15

Therefore, they will be mowing there lawn together again after 15 days.

Hence, the correct answer is D. 15.