Question

$6$ 个男孩的平均体重是 $150$ 磅， $4$ 个女孩的平均体重是 $120$ 磅。这 $10$ 个孩子的平均体重是

The average weight of $6$ boys is $150$ pounds and the average weight of $4$ girls is $120$ pounds. The average weight of the $10$ children is

$135$ 磅

$135$ pounds

$137$ 磅

$137$ pounds

$138$ 磅

$138$ pounds

$140$ 磅

$140$ pounds

$141$ 磅

$141$ pounds

知识点：平均数

总重量是 $6 \times 150$ $+ 4 \times 120$ $= 900 + 480$ $= 1380$ 磅。

$10$ 个孩子的平均体重是 $\dfrac{1380}{10} = 138$ 磅。

所以正确答案是 C。

The total weight is $6 \times 150$ $+ 4 \times 120$ $= 900 + 480$ $= 1380$ pounds.

The average of the $10$ children is $\dfrac{1380}{10} = 138$ pounds.

Thus, the correct answer is C .