1963 TMTA High School Algebra I Contest Problem 38

Problem

A farmer sold $60$ hogs for $$2030.$ Some were sold for $$ 30$, and the remainder were sold for $$ 40$ each. How many were sold at $$ 30$ each?

$\text{(A)} \quad 37; \quad \text{(B)} \quad 19; \quad \text{(C)} \quad 29; \quad \text{(D)} \quad 42; \quad \text{(E)} \quad \text{none of these}$

Solution

If there were $h$ hogs sold at $30$ dollars each, then there were $60-h$ hogs sold at $40$ dollars each. Using this, we can construct an equation which lets us solve for $h$, the number of hogs sold at $30$ dollars each.

\[30h + 40(60-h) = 2030\] \[30h - 40h + 2400 = 2030\] \[-10h = -370\] \[h = \frac{-370}{-10} = 37.\]


The answer is $\boxed{\text{(A)}}$.

See Also

1963 TMTA High School Mathematics Contests (Problems)
Preceded by
Problem 37
TMTA High School Mathematics Contest Past Problems/Solutions Followed by
Problem 39