Problem Solving

Helpers are needed to prepare for the fete. Each helper can make either 2 large cakes per hour, or 35 small cakes per hour. The kitchen is available for 3 hours and 20 large cakes and 700 small cakes are needed. How many helpers are required?
(A) 10
(B) 15
(C) 20
(D) 25
(E) 30

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1 helper 1hr 2L or 35 S cakes

20L and 700 S 3 hr?

1 helper can finish 2L in 1 hr
10 helpers can finish 20L in 1 hr.

1 helper can finish 35S in 1 hr.
10 helpers can finish 350S in 1 hr,700S in 2 hr.

Same 10 helpers can do all tasks in 3 hrs

Pick A

is OA : A(10)

A

700 small cakes can be made by 20 cooks in one hour
20 large cakes can be made by 10 cooks in one hour..

in total 30 cooks are needed in one hour. since we have 3 hours we need only 10 cooks