The phrase "a combination of efficient" is not correct as it is incomplete and lacks a noun to follow "efficient." You can use it when discussing a blend of elements that are efficient, but it needs to be rephrased for clarity.
Example: "The project was a combination of efficient strategies and innovative ideas."
Alternatives: "a blend of effective" or "a mix of productive".
The proposed methodology employs a combination of efficient and accurate analytical and simulation techniques to estimate the probabilistic properties of the structural response under a seismic input modeled as a non-stationary stochastic process.
So, basically, the whole story is that in the United States power sector we're switching from older inefficient coal-fired power generation to a combination of efficient natural gas and renewables.
Through a combination of efficient stock management and direct shipping, stores can require less stock space and fewer staff.
He does not use a sprint finish to win races: his strategy relies upon a combination of efficient running and fast pace setting.
A combination of efficient intracellular accumulation, stability against β-lactamases and target affinity is exhibited by ertapenem for effective antibiotic activity in bacteria.
Importantly, in transduced cells, expression appears to result from a combination of efficient packaging and translation.
To meet Mexico's emission reduction targets, all modeling groups agree that decarbonization of electricity is needed, along with changes in the transport sector, either to more efficient vehicles or a combination of more efficient vehicles and lower carbon fuels.
China and India will use a combination of more efficient coal technology, nuclear energy and renewables to help meet their accelerating demand for energy.
Apple's imaging has in recent years worked so well through a combination of an efficient sensor and good-taste image processing.
Already, providers are experimenting with gigabit speeds in both licensed and unlicensed (Wi-Fi) networks, innovating a combination of more efficient use of spectrum, new antenna and cell design technology, and smarter smartphones that can automatically jump to less congested frequencies.
A combination of the efficient markets theory (EMT) and the wisdom of crowds make stock picking a zero sum game.
