Answer:
C. 10
Step-by-step explanation:
by deduction, 5 and 7 are prime numbers and 15 is not a multiple of 70, therefore the answer must be 10 as it is a non-prime number and is a factor of 70 (I.e. 10 and 7)
Answer:
a non prime factor of 70 is 10
the answer is c.
10 is a multiple of 70