Seats in an auditorium are numbered 1-500, and the principal is handing out snacks in an assembly. Every student whose seat is a multiple of 4 gets chocolate. Every student in a seat that is a multiple of 7 gets jelly beans, and every student in a seat that is a multiple of 10 gets chips.

The student in which seat number is the first to get all 3 treats?

A)40
B)70
C)100
D)140

Question

Seats in an auditorium are numbered 1-500, and the principal is handing out snacks in an assembly. Every student whose seat is a multiple of 4 gets chocolate. Every student in a seat that is a multiple of 7 gets jelly beans, and every student in a seat that is a multiple of 10 gets chips. 

The student in which seat number is the first to get all 3 treats?

A)40	
B)70	
C)100	
D)140

fortytherapper · Answer

If snacks were being handed out, I'm definitely joining

So this is how I would tackle this problem. You have to find a common number. You know how they say Find the common denominator? This is the same. Since you're biggest choice is 140, I would write out multiples of 10 until 140 (10,20,30,40,50, etc). The same with 4 and 7. After that, I would look to see which number showed up all 3 times.

Process of elimination works too. For example, one choice is 40. Does 7 go into 40 evenly? No. So scratch that answer.

fortytherapper · Answer

Actually, do process of elimination, takes 15 seconds